10% efficiency solar cells with 0.5 µm of CdTe

Fabricating high-efficiency CdS/CdTe solar cells with ultra-thin (below 1 μm) absorber layers is a challenging yet highly desirable step in improving CdTe technology. Typically solar cell performance decreases due to shunting, incomplete absorption (deep penetration loss), fully depleted CdTe layers or interference between the main and the back contact junction when the CdTe layer thickness approaches a certain limit. While some of these losses are fundamental, others can be minimized by careful optimization of the fabrication steps. We present the results of such optimization.