The influence of surface modification on optoelectronic properties of monocrystalline silicon solar cells

The porous silicon (PS) layers on the front surface of n/sup +//p monocrystalline, textured silicon solar cells were investigated with the aim to improve the performance of standard screen-printed silicon solar cells. The application of the PS layer is very promising because simultaneous, antireflection coating and surface passivation can be obtained in one chemical process. In this work the improvement of solar cell characteristics due to the formation of PS layer (by stain etching method) between the grid fingers has been demonstrated. Such a surface modification allows reduction of the effective reflectance to about 3% in a wavelength range of 400-1000 nm effecting in increase of short circuit current density (about 10%) and in efficiency of about 16%. The significant increase in the IR and UV ranges of wavelengths on the internal quantum efficiency has been observed. The structure of homogeneous PS layer were investigated using SEM, TEM, and AFM methods.