Toward a 25-efficient polycrystalline thin-film tandem solar cell: practical issues

摘要

In this paper, we describe our efforts to date to evaluate possible routes, combination of materials, and device structures toward demonstrating a multijunction polycrystalline thin-film tandem solar cell with efficiency greater than 25%. Our approach uses modeling as a guide to calculate an approximate upper limit of device performance, the range of band gap pairs for top and bottom cells, and the optical resources/losses through the multilayer structure. The combination of materials we chose for the initial study are based on state-of-the-art single junction devices utilizing Cu(In,Ga)Se/sub 2/ and CdTe absorbers.