Current collection mechanisms in p-n junction a-Si:H solar cells using spectral response analysis

Measurement of short circuit current of P-N junction a-Si:H solar cells shows that photogenerated carriers are collected by field assisted process from the depletion region of the N-I layer in N-I-P devices and the P-I layer in P-I-N devices. The I-layer behaves as an N-layer under the illumination. The results of spectral response analysis indicate a very strong absorption in the doped layer. Reduction of doped layer thickness from a few hundred angstroms to less than 100Å improves J
sc
by 20-30%.