A Method for Uniform Embedment and Self-Assembly of CIS-based QDs for Formation of Ordered QD Thin Films in PV Devices

Quantum dots (QDs) are investigated for photovoltaic (PV) device applications; due to safety concerns regarding the use of Cd, Pb-based materials, less-toxic copper indium sulfide (CIS) and zinc copper indium sulfide (ZCIS) QDs have gained prominence. In advanced PV structures, the formation and morphology of QD films is significant; the construction of uniform, defect-free QD films are desirable. Several strategies are employed in QD film formation, most notably spin-casting, drop-casting, and dip-coating. We studied the film deposition and self-assembly QDs in formation of device-quality films. Using dip-coating, we developed a method to deposit uniform, ordered less-toxic CIS and ZCIS QD films for large-area, scaled-up PV applications.