Solution-Processed Black-Si/Cu2ZnSnS4 Nanocrystal Heterojunctions for Self-Powered Broadband Photodetectors and Photovoltaic Devices

We report, for the first time, the fabrication of n-black Si (B–Si)/p-Cu2ZnSnS4 nanocrystal (CZTS NC) heterojunctions to demonstrate their photodetection and photovoltaic characteristics. Inks with crystalline CZTS NCs can be directly spin coated on an ultralow reflective (5.0%, even without any surface passivation or encapsulation of the device. The combined studies show impactful potential of the B–Si/CZTS NC heterojunction for future high-speed light-sensing and energy-harvesting devices using solution-processed techniques compatible to large area applications.