Poster 1039-Investigation the effect of different methods of

1 / 5

论文编号ID1039（共5页）

Investigation the effect of different methods of light-induced degradation

(LID) for reference solar cells

Zhou Xuefeng ，Yan ping

CHANGZHOU TRINA SOLAR ENERGY CO.，LTD.

Author brief introduction

Abstract: In this paper ，we based on the directional solidification (DSS) method for the growth of P type boron doped polycrystalline silicon materials for solar working reference cell made after light-induced degradation(LID) evaluation ，by using two optical methods to study the effect on the electrical characters of solar cell to find one easy procedure to get the working reference cell in Silicon crystal PV manufactures by comparing the two kinds of degradation method ，ensure the IV electrical characters of solar cell and keep in output stable ，accurate and reliable ，the decay mode to use units and feasible recommendations. Keywords: Working reference cell, light-soaking Simulator, Sunlight house, light-induced degradation (LID)

1 Introduction

P-type boron-doped solar cell light-induced degradation phenomenon is found in the seventies, the company currently degradation method is to use a piece of outdoor solar cell sun room method is direct sunlight outdoors decay, solar cells The degradation can be roughly pided into two stages, the first stage, we can call it an early photoluminescence decay, namely decreased greatly solar cells occurred in the beginning of the degradation of the initial period of time, but then stabilize. The main reason for this phenomenon is the P-type boron-doped silicon crystals in the case of the light degradation produced boron-oxygen complex, reducing the minority carrier lifetime, resulting in the electrical properties of solar cells made of decline. The second phase, solar cells suspected of excessive degradation aging, slow decline that is present in the outdoor long-term decay, leading to increased aging of cells, such as oxidation phenomena appear.

This paper discusses the impact of differences between the two methods of decay brought about by another method is indoor photoluminescence decay with more than one level of light-induced degradation simulators (class C or better), to solar cell light-induced degradation (LID).

2 P-type boron-doped polycrystalline silicon solar cells early light-induced degradation mechanism

（第一作者

2寸照）

Zhou Xuefeng ，now servicing Changzhou Trina Solar Co., Ltd. Job position is reference cell manage engineer. Mainly response for management & reach precision measurement

2 / 5

30 years ago, H. Fischer and W. Pschunder, who first observed the P-type (boron-doped) initial crystalline silicon solar cell light-induced degradation phenomenon, shown in Figure 1.

Figure 1 P-type boron-doped polycrystalline silicon solar cells early light-induced degradation mechanism Then people have done a lot of scientific experiments, in recent years, research found that boron and silicon oxygen concentration, we basically consistent view is: the light or current injection led to the silicon and oxygen to form boron boron-oxygen complexes, thereby reducing the minority carrier lifetime, but after the annealing process, the minority carrier lifetime and can be restored, which may reflect recognized as:

3 P-type boron-doped crystalline silicon solar cell light-induced degradation test

Testing Requirements: Two degradation after the test methods used in batteries and solar simulators are standard pieces with standard sheet (Fraunhofer-ISE calibration), with a solar simulator (Berger flash simulator), degradation test sources are more than 156*156 ordinary crystal cells.

1) Outdoor natural sun room degradation method Test conditions: winter decay cycle 30 days, 60kWh,

standard piece reaches steady decay; indoor simulated sunlight law decay test conditions: indoor degradation 2-3 days, 60kWh, standard piece reaches steady decay. The two methods of degradation before and after the decay electrical properties of aggregate data, see Table 1:

Table 1 both before and after the degradation of the degradation method of electrical performance data

3 / 5

2) Differences two LID methods

Two methods of degradation before and after the degradation electrical performance data are compared, in Table 2, Figure 2:

The two methods of degradation before and after the degradation electrical performance data are compared,

in Table 2,

two ways of LID

SN Uoc[mV] Isc[mA] Rs[m Ω] FF[%] Eff[%] 1_11 1.40 -24.70 -0.2000 0.20 0.03 2_12 0.80 -44.50 -0.1000 0.18 -0.03 3_13 0.60 -72.30 -0.3000 0.27 -0.07 4_14 0.50 -47.70 -0.3000 0.23 -0.03 5_15 2.40 -29.00 -0.2000 0.26 0.07 6_16 1.00 -26.30 -0.3000 0.37 0.06 Ave

1.2000

-40.8000

-0.2000

0.25

0.01

Figure 2: Differences in the electrical properties of the test data in Table 2 are two methods of degradation

3)Contrast difference between the two decay modes, see Table 3:

Table 3, two kinds of methods contrast degradation difference

No. LID(Sunlight

house)

LID(Light-soaki

ng Simulator)

Dev.(Δ) Findings

Uoc 2.4mV 1.2mV 1.20mV voltage decay is insignificant Isc 19.8mA 60.8mA 40.8mA current decay quite different

Rs ‐0.1mΩ0.1mΩ0.20mΩoutdoor degradation resistor string is too large

FF 0.28% 0.03% 0.25%

fill factor large outdoor degradation

Eff 0.17% 0.16% 0.01% efficiency was essentially flat degradation, LID the same status ok

Leader Time 30 days

/60kWh

(Winter)

total 3

days/60kWh

27days

LID of Leader Time sunlight house longer

than light-soaking simulator

4)Experimental Results &Findings

P-type boron-doped crystalline silicon solar cell light-induced degradation solutions: Indoor, outdoor degradation, two ways to achieve the expected initial decay purpose and ultimate degradation difference is small (Cell efficiency Eff). Outdoor decay of aging cells intensifies (Rs have become the trend, FF strong degradation), outdoor than indoor decay cycle longer, outdoor uncontrollable environmental factors are also more (temperature, humidity, cleanliness, etc.), outdoor degradation more severe than the indoor degradation.

In order to improve the production cycle battery label sheet, more pieces in good condition to protect the battery, so that the finished piece battery marked stable, reliable, accurate, standard chip-enabled cell degradation ideal light-soaking simulation.

4 Conclusion

Both methods can achieve the desired purpose decay and eventually decay small difference, but under the current comprehensive evaluation method commonly used in the industry, in order to protect the battery in good condition marked sheet, improve production cycle marked sheet protection and peer benchmarking sell batteries fairness, we recommend the following manner Feasibility

(1) use of the indoor than outdoor degradation is better, is not affected by changes in the weather can reduce the oxidation of the sample, the impact of dust, the time control is good, but the higher cost of equipment purchase and use; this decay mode can be used for battery level scale film production, research test to confirm the results of the standard production and standard piece of emergency; peer commonly used mode;

(2) Outdoor sunlight room degradation, increasing the degree of aging of cells (Rs have a larger trend, FF strong degradation), outdoors than indoors longer period of decay, and uncontrollable environmental factors more so than the indoor outdoor degradation more severe degradation. And a long period, there is some excessive degradation phenomenon. But lower cost, is the way the production line for the production of secondary standard piece more appropriate;

4 / 5

(3) Efficiency monolithic absolute difference of 0.1% -0.2% difference is normal, may be related to the spectral response of the relevant 1st reference cells, is not strongly associated with the decay mode.

Reference

1IEC 60904-11 Photovoltaic devices – Part11:Measurement of initial light-induced degradation of crystalline silicon solar cell and photovoltaic modules CD

2IEC 61215 Ed.3 Crystalline silicon terrestrial photovoltaic(PV)modules-Design qualification and type approval CD

3H. Fischer and W. Pschunder,Proc.10 th IEEE PVSC,1973,p.404.

4 第十届中国太阳能光伏会议论文集《P型掺硼单晶硅太阳电池和组件早期光致衰减问题的研究.张光春等著》

5 / 5

本文来源：https://www.bwwdw.com/article/diqq.html