6.6% efficient antimony selenide solar cells using grain structure control and an organic contact layer

We report a high efficiency antimony selenide (Sb2Se3) photovoltaic device structure using a new multi-step close space sublimation deposition process incorporating a Sb2Se3 seed layer; key to achieving higher efficiency devices via close space sublimation. Utilizing a glass|FTO|TiO2|Sb2Se3|PCDTBT|Au structure, a peak efficiency of 6.6% was achieved, which is comparable to the current record devices for this material. Crucially, this device avoids toxic lead in the hole transport material, and cadmium in the window layer. Moreover, the addition of the PCDTBT back contact both maintains peak efficiency of 6.6%, and improves the uniformity of performance, increasing the average efficiency from 4.3% to 6.1%.