High Performance PbS Colloidal Quantum Dot Solar Cells by Employing Solution‐Processed CdS Thin Films from a Single‐Source Precursor as the Electron Transport Layer

Abstract

CdS thin films are a promising electron transport layer in PbS colloidal quantum dot (CQD) photovoltaic devices. Some traditional deposition techniques, such as chemical bath deposition and RF (radio frequency) magnetron sputtering, have been employed to fabricate CdS films and CdS/ PbS CQD heterojunction photovoltaic devices. However, their power conversion efficiencies (PCEs) are moderate compared with ZnO/PbS and TiO 2 / PbS heterojunction CQD solar cells. Here, efficiencies have been improved substantially by employing solution-processed CdS thin films from a singlesource precursor. The CdS film is deposited by a straightforward spin-coating and annealing process, which is a simple, low-cost, and high-material-usage fabrication process compared to chemical bath deposition and RF magnetron sputtering. The best CdS/PbS CQD heterojunction solar cell is fabricated using an optimized deposition and air-annealing process achieved over 8% PCE, demonstrating the great potential of CdS thin films fabricated by the single-source precursor for PbS CQDs solar cells. Figure 4. a) Temperature-dependent light J-V curves showing a maximum V oc at the minimum temperatures measured and an optimal J sc , FF, and PCE at 260 K. b) Temperature dependence of the characteristic device parameters (PCE, FF, J sc , and V oc ).www.afm-journal.de www.advancedsciencenews.com 1703687 (7 of 7)

Optimizing Surface Chemistry of PbS Colloidal Quantum Dot for Highly Efficient and Stable Solar Cells via Chemical Binding

“…The PbS CQDs were purified three times by precipitation using acetone and centrifugation at 5000 rpm for 30 s according with the reference. [ 6,8 ]…”

Quantum Dot Solar Cells: Small Beginnings Have Large Impacts

“…These ETLs can be self-assembled monolayers (SAMs) formed by treating the metal oxide layer with organic solutions like tetrahydrofuran [184] and aminobenzoic acid [197] or other intermediate buffer layers made of materials like carbon QDs [212], CdSe QDs [214], mixed nanocrystals [188], magnesium-doped ZnO [215] or other organic buffers [216] that have given rise to devices with PCEs >9%. While all these ETLs are used in conjunction with a metal oxide layer, recently, CdS has also been successfully used as an n-type electrode instead of a metal oxide to make a heterojunction QDSC with a PCE of 8% [217].…”

Alkali Metals Doping for High‐Performance Planar Heterojunction Sb2S3 Solar Cells

“…To achieve solar grid parity, a great deal of efforts has been dedicated to the exploration and exploitation of photovoltaic materials that are potentially cost effective. Metal chalcogenides, such as the conventional CdTe, PbS, Cu(In,Ga)Se 2 (CIGS), Cu 2 ZnSn(S,Se) 4 (CZTSSe) and unconventional AgBiS 2 , GeSe, Sb 2 S 3 , Sb 2 Se 3 have attracted widespread attention in the photovoltaic applications towards this goal. In particular, antimony sulfide (Sb­ 2 S 3 ) shows great promise due to its appropriate bandgap (≈1.7–1.8 eV), high absorption coefficient (1.8 × 10 5 cm −1 at 450 nm), relative elemental abundance and environment‐friendly characters .…”