Collection of photocarriers in Ga1-xInxNyAs1-y solar cells

Collection of photocarriers in Ga_1-xIn_xN_yAs_1-y solar cells is limited by the poor quality of the Ga_1-xIn_xN_yAs_1-y. Some reports have shown collection of photocarriers outside of the depleted layer in annealed Ga_1-xIn_xN_yAs_1-y, but the key to achieving the higher collection has been unclear. In this paper, we attempt to quantify the diffusion and collection lengths that contribute to the photocurrent in Ga_1-xIn_xN_yAs_1-y solar cells. The data imply that the effective μτproduct for the lightly doped Ga_1-xIn_xN_yAs_1-y material may vary when a field is applied. We conclude that the fields present in most of our best Ga_1-xIn_xN_yAs_1-y cells are large enough to aid collection of photocarriers.