Figure 2: Electronic properties of Bi-doped PbS QDs and homojunctions with PbS QDs.
From: Heterovalent cation substitutional doping for quantum dot homojunction solar cells
(a) Schematic illustration of the normal and inverted QD-homojunction solar cell geometries. (b) Typical J-V curves of normal (ITO/Bi: PbS (50 nm)/PbS (200 nm)/MoO3/Au/Ag) and inverted (ITO/PbS (150 nm)/Bi:PbS (75 nm)/Ag) homojunctions at dark and at 100 mW cm−2 AM1.5 solar light and (c) EQE spectra of the cells showing efficient photoresponce in Vis-IR. (d) Comparison of Jsc and Voc of normal homojunctions as a function of precursor Bi/Pb ratios for doped QDs. Multiple points refer to multiple device pixels. (e) Summary of ability to form a Schottky junction with different electrode materials and carrier density and type as estimated by Mott–Schottky analysis of Schottky-type devices, as a function of doping concentration. (f) Schematic band diagram of inverted cell with estimated Vbi and depletion widths within p- and n-type layers.
