Study Of Laser Irradiation Damage In CIGS Solar Cells Via Electroluminescence Imaging

Copper indium gallium selenide solar cell（CIGS）is a kind of thin film solar cell with high photoelectric conversion efficiency and good radiation resistance.It has wide application prospects in both civil and military fields.CIGS solar cells can supply power to satellites in orbit and can be the receiver of wireless laser energy transfer technology,etc.Therefore,it is of great significance and value to study continuous laser irradiated CIGS solar cells.There are few reports on the research experiments of laser irradiated CIGS solar cells at home and abroad,therefore,this paper takes the wireless laser energy transfer technology as an opportunity to select532 nm continuous laser irradiated CIGS solar cells by an EL（Electroluminescence）technique combined with a distributed equivalent circuit model of solar cells.The main work of this paper is as follows:1.Based on the structure of the CIGS solar cell and its double diode equivalent circuit,a distributed equivalent circuit model of the solar cell is constructed using the SPICE tool.The I-V characteristics and the EL intensity distribution of this cell before laser irradiation are obtained experimentally,and the parameter values of the subcircuits in this distributed circuit model are determined by parameter adjustment and multiple iterations.2.Build the laser irradiated solar cell light path,determine the laser type and laser wavelength,and calculate the spot size of the laser irradiated to the surface of the cell by the knife-edge measurement.Different laser power densities are used to irradiate the solar cell at different locations,and the laser damage threshold to the CIGS solar cell is determined by analyzing the efficiency after each irradiation.The differences in the types of damage to CIGS cells by different laser power densities were also determined and generalized by means of a distributed circuit model.3.Using optical microscopy,scanning electron microscopy,X-ray spectral analysis and other microscopic means to observe the morphology of the damage caused by different power densities,surface element content,and heat distribution simulation,we analyze the differences in damage mechanisms of CIGS solar cells by different laser power densities,and finally agree with the conclusions reached by EL technique combined with distributed circuit model.The results are consistent with the EL technique combined with distributed circuit model,which further validates the innovation and accuracy of the method.