Effects of polarization charge on the photovoltaic properties of InGaN solar cells

The effects of interface polarization charge on the photovoltaic characteristics of GaN/InGaN solar cells have been analyzed in detail using 2D drift-diffusion simulations. The polarization charge at the GaN/InGaN interface creates an electric field that forces carriers generated by light to drift in opposite direction needed for efficient collection and substantially reduces the short circuit current (I-sc) and open circuit voltage (V-oc). The polarization charge plays an important role in the photovoltaic properties of InGaN solar cells comparable to that of defects. For small interface charge, the potential barrier could increase the V-oc. (c) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim