Selenium-fullerene heterojunction solar cell

A method of forming a solar cell, the method comprising the steps of:

• forming a front contact on a substrate;
• depositing an n-type semiconducting layer on the front contact, wherein the n-type semiconducting layer comprises a fullerene or fullerene derivative;
• forming a p-type chalcogen absorber layer on the n-type semiconducting layer;
• depositing a high workfunction material onto the p-type chalcogen absorber layer, wherein the high workfunction material has a workfunction of greater than about 5.2 electron volts;
• forming a back contact directly on the high workfunction material, wherein the high workfunction material, as deposited, and the back contact, as formed, comprise continuous layers that fully cover a top surface of the p-type chalcogen absorber layer;
• and
• patterning the continuous layers of the high workfunction material and the back contact whereby, following the patterning, the high workfunction material and the back contact are located off to one side of the solar cell and covering a portion of the top surface of the p-type chalcogen absorber layer while another portion of the p-type chalcogen absorber layer is uncovered.