Air-Stable and Efficient PbSe Quantum-Dot Solar Cells Based upon ZnSe to PbSe Cation-Exchanged Quantum Dots.

Kim, Sungwoo; Marshall, Ashley R; Kroupa, Daniel M; Miller, Elisa M; Luther, Joseph M; Jeong, Sohee; Beard, Matthew C · ACS Nano · 2015

basic_science · Level V

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Abstract

We developed a single step, cation-exchange reaction that produces air-stable PbSe quantum dots (QDs) from ZnSe QDs and PbX2 (X = Cl, Br, or I) precursors. The resulting PbSe QDs are terminated with halide anions and contain residual Zn cations. We characterized the PbSe QDs using UV-vis-NIR absorption, photoluminescence quantum yield spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy. Solar cells fabricated from these PbSe QDs obtained an overall best power conversion efficiency of 6.47% at one sun illumination. The solar cell performance without encapsulation remains unchanged for over 50 days in ambient conditions; and after 50 days, the National Renewable Energy Laboratory certification team certified the device at 5.9%.