A green synthesis of CISe nanocrystal ink and preparation of quantum dot sensitized solar cells

Abstract

I–III–VI chalcopyrite copper indium selenium is one of therepresentatives of the light absorbing layer material, and is often used for a thin-film solar cell. With the development of nano-technology, CuInSe2 quantum dots (CISe QDs) which have intermediate belt and excitation effect characteristics are applied to the solar cells as an alternative of Cd- or S-based QDs. Most conventional methods for the synthesis of CISe QDs using solution involve the dangerous and environmentally unfriendly Oleylamine or phosphine coordination compounds. In this work, CISe QDs were synthesized by a green, safe and low-temperature method in triethylene glycol. Through controlling the growth temperature and time, the diameter can be adjusted from 3[Formula: see text]nm to 10[Formula: see text]nm. The samples exhibit quantum confinement effect, and have a controllable optical band gap. QDs were deposited on the surface of ZnO nanorods to obtain a photoanode, which were fabricated into quantum dot-sensitized solar cells. The device exhibits size-dependent performance. And the open circuit voltage shows a fluctuation up to 0.26[Formula: see text]V. When the size is 4[Formula: see text]nm, the short circuit current density is the largest (15[Formula: see text]mA/cm2).