太阳能电池开路电压非接触定量成像检测

太阳能电池的开路电压(Voc)是影响太阳能电池的光电转化效率重要参数之一.为了准确检测太阳能电池开路电压图像，首先利用有限元仿真方法得到了太阳能电池开路电压与发光成像强度之间的关系；其次基于调制光致载流子锁相成像(LIC)系统对商用单晶硅太阳能电池和多晶硅太阳能电池进行了开路电压非接触定量成像研究，并与光致发光成像检测方法(PL)对比；最后利用LIC方法对不同注量1 MeV电子辐照GaAs太阳能电池进行开路电压成像研究.结果表明：LIC方法和PL方法均能获得太阳能电池的开路电压分布，且两种方法所测得的单晶硅太阳能电池和多晶硅太阳能电池开路电压均值均与Sun-Voc方法所测结果一致，误差小于1%.利用LIC方法测得开路电压分布结果与PL检测方法吻合，相比PL检测方法，LIC检测结果信噪比更高，且检测过程更简单；对不同注量1 MeV电子辐照的GaAs电池的开路电压进行LIC成像的结果与电测结果吻合，为分析辐照电池局部损伤提供了一种新方法.
The open-circuit voltage of a solar cell is one of the key parameters for conversion efficiency. In order to contactlessly and quantitatively image the open-circuit voltage of solar cells, in this paper, the relationship between the luminescence intensity and the open-circuit voltage (Voc) of solar cells was firstly simulated by finite element technique (FEM). Secondly, the Voc images of a crystalline silicon (c-Si) solar cell and a multicrystalline silicon (mc-Si) solar cell were quantitatively investigated by lock-in carrierography (LIC) as well as the existed photoluminescence (PL) method. In order to validate the imaging method, Sun-Voc was employed to measure the open-circuit voltage of the crystalline silicon (c-Si) solar cell and the multicrystalline silicon (mc-Si) solar cell. Finally, the open voltage images of GaAs solar cells irradiated by 1 MeV electrons with different fluences were studied by LIC. The result shows: the averaged Voc values by both imaging methods were in good agreements with the results measured by Sun-Voc, and the average values of LIT and PL for two kinds of solar cells differed less than 1% compared with Sun-Voc. Furthermore, the Voc image by LIC was consistent with PL. Compared to PL measurements, LIC has a higher signal-to-noise-ratio (SNR) as well as a simpler detection process. The Voc degradation of electron irradiation GaAs solar cells measured by LIC was in a good agreement with electrical measurement.Therefore, LIC could provide a possible approach to achieve more quantitative characterization of spatially resolved information and a new method to investigate the irradiated solar cell for space use.