Lead antimony sulfides are rare in nature and relatively unexplored ternary semiconductors. This work
investigates the photovoltaic performance of PbeSbeS quantum dot-sensitized solar cells (QDSCs).
Pb5Sb8S17 nanoparticles are grown on mesoporous TiO2 electrodes using the successive ionic layer
adsorption reaction process. The synthesized Pb5Sb8S17 nanoparticles exhibit two attractive features for a
good solar absorber material: a high optical absorption coefficient and a near optimal energy gap. Solidstate
QDSCs are fabricated from the synthesized Pb5Sb8S17 nanoparticles using Spiro-OMeTAD as the
hole-transporting material. The best cell yields a short-circuit current density Jsc of 11.92 mA cm2, an
open-circuit voltage Voc of 0.48 V, a fill factor FF of 30.7% and a power conversion efficiency (PCE) of 1.76%
under 1sun. The external quantum efficiency (EQE) spectrum covers a spectral range of 350e800 nm
with a maximal EQE ¼ 65% at l ¼ 450 nm. At the reduced light intensity of 10% sun, the PCE increases to
4.14% with Jsc ¼ 2.0 mA cm2 (which could be normalized to 20 mA cm2 under 1 sun). This PCE is 65%
higher than the best previous result. The respectable PCE and Jsc indicate that Pb5Sb8S17 could be a
potential candidate for a solar absorber material