AN ACCURATE ANALYTICAL APPROACH INCLUDING INTERNAL REFLECTANCE FOR CALCULATING QUANTUM EFFICIENCY OF PLANAR SOLAR CELLS

摘要

An analytical approach for calculating the quantum efficiency of a planar Si solar cell is presented, which is as accurate as the numerical simulation program PC1D v. 5.1. The device under exam is partitioned into regions by applying the depletion approximation. In the non-uniformly doped emitter, the quantum efficiency is calculated analytically by using a reported iterative solution to minority-carrier transport. In the uniformly doped base, it is calculated by solving the minority-carrier transport at boundary conditions for optical spike generation. In the depletion region, it is calculated with the textbook expression. In all of the analytical expressions, a reported optical generation profile function is included, where the internal reflectance values do not depend on the successive encounters of light with internal surfaces, and the average angle of propagation of light is imposed to be zero at all wavelengths. The equivalence between the analytical approach and PC1D v. 5.1 is shown experimentally by fitting quantum efficiency and external reflectance data of actual devices.