CN105244392A - Photovoltaic cell applied to automobile roof for improving shadow shading reliability, and manufacturing method thereof - Google Patents

Abstract

Translated fromChinese

本发明公开了一种用于汽车车顶棚提高阴影遮挡可靠性的光伏电池及其制备方法，所述光伏电池包括：一硅片衬底；扩散区层，设置于所述硅片衬底的同一表面，包括间隔的若干N型扩散区和若干P型扩散区；第一钝化层，形成于所述扩散区层上；电极接触层，包括若干N型电极接触和若干P型电极接触，分别形成于所述N型扩散区和P型扩散区上；第二钝化层，设置于所述硅片衬底与所述扩散区层相反的另一表面。本发明构成横向PN结，在阴影遮挡时多个横向PN结对反向漏电流进行分流，降低了单位面积上的反向漏电流密度，从而降低了电池片在反偏时的发热量，提高了电池的阴影遮挡可靠性，同时极大提高了光伏电池的抗热斑能力，可以很好的与汽车车顶棚结合起来。

The invention discloses a photovoltaic cell for improving the reliability of shadow shielding on the roof of an automobile and a preparation method thereof. The photovoltaic cell comprises: a silicon wafer substrate; a diffusion layer arranged on the same surface of the silicon wafer substrate; The surface includes several N-type diffusion regions and several P-type diffusion regions at intervals; the first passivation layer is formed on the diffusion region layer; the electrode contact layer includes several N-type electrode contacts and several P-type electrode contacts, respectively It is formed on the N-type diffusion region and the P-type diffusion region; the second passivation layer is arranged on the other surface of the silicon wafer substrate opposite to the diffusion region layer. The invention forms a lateral PN junction, and multiple lateral PN junctions shunt the reverse leakage current when the shadow is blocked, reducing the reverse leakage current density per unit area, thereby reducing the calorific value of the cell when it is reverse biased, and improving the The shadow shielding reliability of the battery greatly improves the anti-hot spot ability of the photovoltaic battery, which can be well combined with the roof of the car.

Description

Translated fromChinese

一种用于汽车车顶棚提高阴影遮挡可靠性的光伏电池及其制备方法Photovoltaic cell for improving the reliability of shadow shading for automobile roof and preparation method thereof

技术领域technical field

本发明属于光伏电池技术领域，具体涉及一种用于汽车车顶棚提高阴影遮挡可靠性的光伏电池及其制备方法。The invention belongs to the technical field of photovoltaic cells, and in particular relates to a photovoltaic cell and a preparation method thereof for improving the reliability of shadow shielding on automobile roofs.

背景技术Background technique

目前，新能源汽车是一个非常具有前景的研究方向。将光伏电池与汽车相结合，将光伏组件与汽车车顶棚融为一体的设计非常引人关注。但是，汽车在行驶或者停靠过程中，很容易受到树叶、建筑物、鸟粪、广告牌等的遮挡。对常规电池而言，这很容易产生热斑，从而导致组件烧毁。At present, new energy vehicles are a very promising research direction. The design of combining photovoltaic cells with automobiles and integrating photovoltaic modules with automobile roofs is very attractive. However, when a car is running or parked, it is easily blocked by leaves, buildings, bird droppings, billboards, etc. With conventional batteries, this can easily create hot spots that can burn components.

具体来说，晶体硅光伏电池一般采用P型硅片衬底，经过扩散在P型衬底的受光面形成N型掺杂区，形成PN结，PN结的方向与入射光的方向相同。当光伏组件受到阴影遮挡时，被遮挡电池片工作在反向偏压状态。在反向偏压下，反向漏电流一般以垂直于PN结的界面方向流动。对于常规电池，由于在电池的边缘存在大量的缺陷态，同时边缘处PN结的扩散区相对其他区域是浅扩区，漏电流一般将通过电池的边缘流动。在遭受阴影遮挡时，电池工作在反偏状态，由于边缘处面积小，因此通过边缘区域的漏电流密度很高，较大的漏电流流动在边缘形成较高的热量，形成热斑，容易将电池片以及封装的EVA、背板等材料烧毁。Specifically, crystalline silicon photovoltaic cells generally use a P-type silicon wafer substrate. After diffusion, an N-type doped region is formed on the light-receiving surface of the P-type substrate to form a PN junction. The direction of the PN junction is the same as the direction of the incident light. When the photovoltaic module is shaded, the shaded cells work in a reverse bias state. Under reverse bias, the reverse leakage current generally flows in the direction perpendicular to the interface of the PN junction. For conventional batteries, since there are a large number of defect states at the edge of the battery, and the diffusion region of the PN junction at the edge is a shallow expansion region compared to other regions, the leakage current will generally flow through the edge of the battery. When shaded, the battery works in the reverse bias state. Due to the small area at the edge, the leakage current density through the edge area is very high. The larger leakage current flows on the edge to generate higher heat and form hot spots, which are easy to be damaged. Materials such as battery sheets, packaged EVA, and backplanes were burned.

以图1所示的常规光伏电池结构示意图为示意，在156mm×156mm的P型硅片衬底1的一表面上通过磷扩散制备N型区域2，形成发射极；P型衬底1和N型发射极2构成PN结。在N型发射极的上方通过PECVD沉积钝化膜3，然后通过丝网印刷和烧结在该表面形成N型金属电极接触4，在P型衬底1的另一表面形成一P型金属电极接触5。Taking the schematic diagram of the conventional photovoltaic cell structure shown in Figure 1 as a schematic diagram, an N-type region 2 is prepared by phosphorus diffusion on one surface of a P-type silicon wafer substrate 1 of 156 mm × 156 mm to form an emitter; the P-type substrate 1 and the N-type Type emitter 2 forms a PN junction. Passivation film 3 is deposited by PECVD above the N-type emitter, and then an N-type metal electrode contact 4 is formed on the surface by screen printing and sintering, and a P-type metal electrode contact is formed on the other surface of the P-type substrate 1 5.

这种常规的光伏电池结构，由于边缘存在大量的缺陷、杂质，在电池的边缘区域6将引入大量的缺陷态。In this conventional photovoltaic cell structure, since there are a large number of defects and impurities at the edge, a large number of defect states will be introduced into the edge region 6 of the cell.

如图2示意了边缘区域6的能带结构，根据该图示，在P型衬底的区域I和N型发射极2的区域II之间的边缘区域6，图示为区域VI引入了大量的缺陷能级，在N型发射极的区域II导带中的电子很容易通过边缘区域VI的缺陷能级与区域I的价带中的空穴复合，产生漏电流。由于漏电流仅仅集中在两侧，面积很小，因此漏电流密度很高，在两侧流过是产生大量的热量，形成热斑，容易烧毁电池和封装材料。Figure 2 schematically shows the energy band structure of the edge region 6, according to the illustration, in the edge region 6 between the region I of the P-type substrate and the region II of the N-type emitter 2, a large amount of The electrons in the region II conduction band of the N-type emitter can easily recombine with the holes in the valence band of the region I through the defect level of the edge region VI, resulting in leakage current. Since the leakage current is only concentrated on both sides and the area is small, the leakage current density is very high, and a large amount of heat is generated when it flows on both sides, forming hot spots, which is easy to burn the battery and packaging materials.

发明内容Contents of the invention

因此，针对上述问题，本发明提出了一种用于汽车车顶棚的光伏电池器件结构，该结构能够降低光伏电池的漏电流密度，使光伏电池即便在遮挡时也不产生热斑。Therefore, in view of the above problems, the present invention proposes a photovoltaic cell device structure for the roof of an automobile, which can reduce the leakage current density of the photovoltaic cell, so that the photovoltaic cell does not generate hot spots even when it is shaded.

本发明的目的是提供一种用于汽车车顶棚提高阴影遮挡可靠性的光伏电池及其制备方法，所述的光伏电池主要包括硅片衬底，其特征在于，在硅片衬底的同一表面形成阵列式N型和P型的重扩散区，构成横向PN结，在阴影遮挡时多个横向PN结对反向漏电流进行分流，降低了单位面积上的反向漏电流密度，从而降低了电池片在反偏时的发热量，提高了电池的阴影遮挡可靠性。The object of the present invention is to provide a photovoltaic cell and its preparation method for improving the reliability of shadow shielding on the roof of an automobile. The photovoltaic cell mainly includes a silicon wafer substrate, which is characterized in that, An array of N-type and P-type heavy diffusion regions is formed to form a lateral PN junction. When shaded, multiple lateral PN junctions shunt the reverse leakage current, reducing the reverse leakage current density per unit area, thereby reducing battery life. The calorific value of the sheet during reverse biasing improves the shadow blocking reliability of the battery.

本发明揭示了一种用于汽车车顶棚提高阴影遮挡可靠性的光伏电池，其特征在于，所述光伏电池包括：一硅片衬底；扩散区层，设置于所述硅片衬底的同一表面，包括间隔的若干N型扩散区和若干P型扩散区；第一钝化层，形成于所述扩散区层上；电极接触层，包括若干N型电极接触和若干P型电极接触，分别形成于所述N型扩散区和P型扩散区上；第二钝化层，设置于所述硅片衬底与所述扩散区层相反的另一表面。The present invention discloses a photovoltaic cell used for the roof of an automobile to improve the reliability of shadow shielding, which is characterized in that the photovoltaic cell comprises: a silicon wafer substrate; The surface includes several N-type diffusion regions and several P-type diffusion regions at intervals; the first passivation layer is formed on the diffusion region layer; the electrode contact layer includes several N-type electrode contacts and several P-type electrode contacts, respectively It is formed on the N-type diffusion region and the P-type diffusion region; the second passivation layer is arranged on the other surface of the silicon wafer substrate opposite to the diffusion region layer.

比较好的是，本发明揭示的一种用于汽车车顶棚提高阴影遮挡可靠性的光伏电池，其特征在于：所述硅片衬底为P型衬底或N型衬底中的一种。More preferably, the photovoltaic cell disclosed in the present invention is used for improving the reliability of shadow shielding on the roof of an automobile, which is characterized in that: the silicon wafer substrate is one of a P-type substrate or an N-type substrate.

比较好的是，本发明揭示的一种用于汽车车顶棚提高阴影遮挡可靠性的光伏电池，其特征在于：所述扩散区层中所述N型扩散区和所述P型扩散区的间隔排列方式包括线状排列，或者点状排列中一种，或其组合。Preferably, a photovoltaic cell for improving the reliability of shadow shielding disclosed by the present invention is characterized in that: the interval between the N-type diffusion region and the P-type diffusion region in the diffusion region layer is The arrangement includes one of linear arrangement, or dot arrangement, or a combination thereof.

比较好的是，本发明揭示的一种用于汽车车顶棚提高阴影遮挡可靠性的光伏电池，其特征在于：所述第一、第二钝化层的成分包含三氧化二铝、二氧化硅、氮化硅、非晶硅中的一种或几种。Preferably, a photovoltaic cell for improving the reliability of shadow shielding disclosed by the present invention is characterized in that: the composition of the first and second passivation layers includes aluminum oxide, silicon dioxide , silicon nitride, amorphous silicon or one or more.

比较好的是，本发明揭示的一种用于汽车车顶棚提高阴影遮挡可靠性的光伏电池，其特征在于：所述电极接触层包含铝、镍、铜、银、锡、铟、锌及其氧化物中的一种或几种。Preferably, the photovoltaic cell disclosed in the present invention is used for improving the reliability of shadow shielding on the roof of an automobile, and is characterized in that: the electrode contact layer includes aluminum, nickel, copper, silver, tin, indium, zinc and other One or more of the oxides.

本发明还揭示了一种根据上述任何一项的一种用于汽车车顶棚提高阴影遮挡可靠性的光伏电池的制备方法，其特征在于，所述方法包括：The present invention also discloses a method for preparing a photovoltaic cell for improving the reliability of shadow shading on the roof of an automobile according to any of the above items, characterized in that the method includes:

步骤一，在所述硅片衬底上制备所述若干N型发射极和若干P型重掺杂区域，形成所述若干N型扩散区和若干P型扩散区；Step 1, preparing the plurality of N-type emitters and several P-type heavily doped regions on the silicon wafer substrate to form the plurality of N-type diffusion regions and several P-type diffusion regions;

步骤二，形成所述第一、第二钝化层；Step 2, forming the first and second passivation layers;

步骤三，形成若干N型电极接触和若干P型电极接触，在高温烧结过程中所述N型电极接触和所述P型电极接触烧穿形成所述第一钝化层，分别于所述N型发射极和所述P型重扩散区形成良好的欧姆接触。Step 3, forming a number of N-type electrode contacts and a number of P-type electrode contacts. During the high-temperature sintering process, the N-type electrode contacts and the P-type electrode contacts are burnt through to form the first passivation layer, respectively. A good ohmic contact is formed between the P-type emitter and the P-type heavy diffusion region.

比较好的是，本发明揭示的一种用于汽车车顶棚提高阴影遮挡可靠性的光伏电池的制备方法，其特征在于，Preferably, a method for preparing a photovoltaic cell for improving the reliability of shadow shielding disclosed by the present invention is characterized in that:

所述形成第一、第二钝化层的步骤采用介质膜进行钝化，进一步包括：The step of forming the first and second passivation layers adopts a dielectric film for passivation, further comprising:

通过PECVD沉积30nm的Al₂O₃以及50nm的SiNx进行表面钝化，形成所述第一钝化层，同时通过PECVD在所述光伏电池的另一表面20nm的Al₂O₃以及100nm的SiNx进行表面钝化，形成所述第二钝化层。Deposit_30nm Al₂ O₃ and 50nm_SiNx by PECVD for surface passivation to form the first passivation layer. The surface is passivated to form the second passivation layer.

比较好的是，本发明揭示的一种用于汽车车顶棚提高阴影遮挡可靠性的光伏电池的制备方法，其特征在于，Preferably, a method for preparing a photovoltaic cell for improving the reliability of shadow shielding disclosed by the present invention is characterized in that:

所述步骤三中进一步包括，通过丝网印刷的方式形成所述若干N型电极接触和所述若干P型电极接触。The third step further includes forming the plurality of N-type electrode contacts and the plurality of P-type electrode contacts by screen printing.

采用上述结构和方法步骤的光伏电池及制备方法，具有如下的有益效果：The photovoltaic cell and the preparation method adopting the above structure and method steps have the following beneficial effects:

(1)在硅片衬底的同一表面形成阵列式N型和P型的重扩散区，构成横向PN结，在阴影遮挡时多个横向PN结对反向漏电流进行分流，降低了单位面积上的反向漏电流密度，从而降低了电池片在反偏时的发热量，提高了电池的阴影遮挡可靠性。(1) An array of N-type and P-type re-diffusion regions are formed on the same surface of the silicon wafer substrate to form a lateral PN junction. When the shadow is blocked, multiple lateral PN junctions shunt the reverse leakage current, reducing the leakage current per unit area. The reverse leakage current density is high, thereby reducing the heat generation of the cell when it is reverse-biased, and improving the shadow blocking reliability of the cell.

(2)采用该设计，极大提高了光伏电池的抗热斑能力，可以很好的与汽车车顶棚结合起来，适合于制备新能源汽车。(2) With this design, the anti-hot spot ability of the photovoltaic cell is greatly improved, and it can be well combined with the roof of the car, which is suitable for the preparation of new energy vehicles.

附图说明Description of drawings

下面，参照附图，对于熟悉本技术领域的人员而言，从对本发明方法的详细描述中，本发明的上述和其他目的、特征和优点将显而易见。Hereinafter, the above and other objects, features and advantages of the present invention will be apparent to those skilled in the art from the detailed description of the method of the present invention with reference to the accompanying drawings.

图1是目前常规电池剖面结构图；Figure 1 is a cross-sectional structure diagram of a conventional battery at present;

图2是常规电池边缘的能带结构图；Fig. 2 is the energy band structure figure of conventional cell edge;

图3是本发明提供的一种横向PN结电池结构示意图。Fig. 3 is a schematic structural diagram of a lateral PN junction battery provided by the present invention.

附图标记reference sign

1――P型衬底1 - P-type substrate

2――N型发射极2 - N-type emitter

3――第一钝化层3 - the first passivation layer

4――N型电极接触4 - N-type electrode contact

5――P型电极接触5 - P-type electrode contact

6――边缘区域6 - Edge area

7――P型重扩散区7—P-type heavy diffusion region

8――第二钝化层8 - the second passivation layer

具体实施方式detailed description

第一实施例first embodiment

本发明提供的一种用于汽车车顶棚提高阴影遮挡可靠性的光伏电池结构如图3所示。具体的制备步骤包括：首先，选用156mm×156mm的P型衬底1，采用掩模的方式在同一表面上通过磷扩散制备N型发射极2，并通过硼扩散制备P型重掺杂区域7；A structure of a photovoltaic cell used in the roof of an automobile to improve the reliability of shadow shading provided by the present invention is shown in FIG. 3 . The specific preparation steps include: first, select a P-type substrate 1 of 156mm×156mm, and prepare an N-type emitter 2 on the same surface by means of a mask through phosphorus diffusion, and prepare a P-type heavily doped region 7 through boron diffusion ;

其次，在该表面通过PECVD沉积30nm的Al₂O₃以及50nm的SiNx进行表面钝化，制备表面钝化层3，同时通过PECVD在本发明的光伏电池的相对另一表面20nm的Al₂O₃以及100nm的SiNx进行表面钝化，制备表面第二钝化层8；Secondly, deposit 30nm Al₂ O₃ and 50nm SiNx on the surface by PECVD for surface passivation to prepare the surface passivation layer 3, and simultaneously pass PECVD on the opposite surface of the photovoltaic cell of the present invention 20nm Al₂ O₃ and 100nm SiNx for surface passivation to prepare the second passivation layer 8 on the surface;

第三，通过丝网印刷的方式在光伏电池的N型发射极2上形成若干N型电极接触4，在光伏电池的P型重扩散区7形成若干P型电极接触5，在高温烧结过程中，N型电极接触4和P型电极接触5烧穿第一钝化层3，分别于N型发射极2和P型重扩散区7形成良好的欧姆接触。Third, several N-type electrode contacts 4 are formed on the N-type emitter 2 of the photovoltaic cell by screen printing, and several P-type electrode contacts 5 are formed on the P-type heavy diffusion region 7 of the photovoltaic cell. , the N-type electrode contact 4 and the P-type electrode contact 5 burn through the first passivation layer 3 to form good ohmic contacts on the N-type emitter 2 and the P-type heavy diffusion region 7 respectively.

采用上述方式制备的光伏电池，由于其PN结的方向与前述图1中常规电池PN结方向互相垂直，称之为横向PN结。由于在前表面形成了多个PN结的阵列，在遮挡时，漏电流在每一个P型重扩散区7和N型发射极2之间的界面流通。由于在整个前表面分布大量的PN结，都可以对漏电流进行分流，相当于降低了漏电流的电流密度，也降低了电池片在反向漏电的发热量，防止了热斑的产生，适用于经常遭受阴影遮挡的汽车车顶棚应用。The photovoltaic cell prepared in the above manner is called a lateral PN junction because the direction of its PN junction is perpendicular to the direction of the PN junction of the conventional battery in FIG. 1 . Since a plurality of PN junction arrays are formed on the front surface, leakage current flows through the interface between each P-type heavy diffusion region 7 and the N-type emitter 2 during shielding. Since a large number of PN junctions are distributed on the entire front surface, the leakage current can be shunted, which is equivalent to reducing the current density of the leakage current, and also reducing the heat generation of the battery sheet in the reverse leakage, preventing the generation of hot spots. For automotive headliner applications that are often subject to shadowing.

前面提供了对较佳实施例的描述，以使本领域内的任何技术人员可使用或利用本发明。对这些实施例的各种修改对本领域内的技术人员是显而易见的，可把这里所述的总的原理应用到其他实施例而不使用创造性。因而，本发明将不限于这里所示的实施例，而应依据符合这里所揭示的原理和新特征的最宽范围。The foregoing description of the preferred embodiment is provided to enable any person skilled in the art to make or utilize the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles described herein can be applied to other embodiments without the use of inventive step. Therefore, the present invention shall not be limited to the embodiments shown here, but shall be based on the widest scope consistent with the principles and novel features disclosed herein.

Claims (8)

1. improve for Automobile ceiling the photovoltaic cell that shade blocks reliability, it is characterized in that, described photovoltaic cell comprises:

One silicon chip substrate;

Diffusion region layer, is arranged at the same surface of described silicon chip substrate, comprises some N-type diffusion regions at interval and some p type diffusion regions;

First passivation layer, is formed in described diffusion region layer;

Contact electrode layer, comprises the contact of some N-type electrode and contacts with some P-type electrode, be formed on described N-type diffusion region and p type diffusion region respectively;

Second passivation layer, is arranged at another surface that described silicon chip substrate is contrary with described diffusion region layer.

2. a kind of photovoltaic cell blocking reliability for Automobile ceiling raising shade according to claim 1, is characterized in that:

Described silicon chip substrate is the one in P type substrate or N-type substrate.

3. a kind of photovoltaic cell blocking reliability for Automobile ceiling raising shade according to claim 2, is characterized in that:

Described in described diffusion region layer, the spaced arrangement of N-type diffusion region and described p type diffusion region comprises the linear alignment, or a kind of in point-like arrangement, or its combination.

4. a kind of photovoltaic cell blocking reliability for Automobile ceiling raising shade according to claim 3, is characterized in that,

The composition of first, second passivation layer described comprises one or more in alundum (Al2O3), silicon dioxide, silicon nitride, amorphous silicon.

5. a kind of photovoltaic cell blocking reliability for Automobile ceiling raising shade according to claim 4, is characterized in that,

Described contact electrode layer comprises one or more in aluminium, nickel, copper, silver, tin, indium, zinc and oxide thereof.

6. improve for Automobile ceiling the preparation method that shade blocks the photovoltaic cell of reliability according to a kind of of any one in claim 1 to 5, it is characterized in that, described method comprises:

Step one, at the same surface described some N-type emitters of preparation and some P type heavily doped regions of described silicon chip substrate, forms described some N-type diffusion regions and some p type diffusion regions;

Step 2, forms first, second passivation layer described;

Step 3, form the contact of some N-type electrode to contact with some P-type electrode, described in high-temperature sintering process, N-type electrode contact contacts with described P-type electrode to burn and forms described first passivation layer, forms good ohmic contact respectively at described N-type emitter and the heavy diffusion region of described P type.

7. a kind of preparation method of blocking the photovoltaic cell of reliability for Automobile ceiling raising shade according to claim 6, is characterized in that,

The step of described first, second passivation layer of formation adopts deielectric-coating to carry out passivation, comprises further:

The Al of 30nm is deposited by PECVD₂o₃and the SiNx of 50nm carries out surface passivation, form described first passivation layer, simultaneously by the Al of PECVD another surperficial 20nm described in described photovoltaic cell₂o₃and the SiNx of 100nm carries out surface passivation, form described second passivation layer.

8. a kind of preparation method of blocking the photovoltaic cell of reliability for Automobile ceiling raising shade according to claim 7, is characterized in that,

Described step 3 comprises further, forms described some N-type electrode contacts contact with described some P-type electrode by the mode of silk screen printing.