The fabrication and analysis of a PbS nanocrystal:C₆₀bilayer hybrid photovoltaic system

Abstract

A near-infrared sensitive hybrid photovoltaic system between PbS nanocrystals (PbS-NCs) and C(60) is demonstrated. Up to 0.44% power conversion efficiency is obtained under AM1.5G with a short circuit current density (J(sc)) of 5 mA cm(-2) when the PbS-NC layer is treated in anhydrous methanol. The observed J(sc) is found be approximately one-third of the maximum expected from this hybrid configuration, indicating the potential for further optimization. Crucial for device operation, a smooth film of nanocrystals is seen to form on the hole transporting poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) layer deposited on the transparent electrode, facilitated through an ionic interaction between nanocrystal capping ligands and the PEDOT:PSS. The formation of the open circuit voltage in this system is seen to be influenced by an interfacial dipole formed at the hole-extracting electrode, providing insights for further optimization.

Pulsed Laser Ablation based Direct Synthesis of Single‐Wall Carbon Nanotube/PbS Quantum Dot Nanohybrids Exhibiting Strong, Spectrally Wide and Fast Photoresponse

“…The unique properties of nanoscale materials such as carbon nanotubes (CNTs) and quantum dots (QDs) continue to attract an ever increasing attention from both fundamental and applications viewpoints 1–5. Their successful integration into optoelectronic devices has confirmed their potential to achieve novel devices with highly promising performance 6, 7. In particular, photocurrent generation from photovoltaic (PV) and photoconductive (PC) devices containing CNTs and/or semiconducting QDs are being widely investigated 8, 9.…”

Highly efficient cross-linked PbS nanocrystal/C<inf>60</inf> hybrid heterojunction photovoltaic cell

“…The PbS NC thin film was treated with methanol to remove the surface ligand. [5] For the BDT capped PbS NC as presented in this study, there is no reduction of V OC in the heterojunction devices. As the V OC is mainly determined by the build-in potential established in the depletion region in PbS NC layer.…”

Organic–Inorganic Solar Cells: Recent Developments and Outlook

“…This, believed to be caused by chemisorption between the bulyamine moiety and the PSS groups, made possible the deposition of thin films of NCs (~100 nm) without pinholes reducing shorting. The deposited NC films were further pre-treated by immersing in methanol, which removed the residual ligands resulting in a dramatic increase of the J sc up to 5 mA/cm 2 and thirty fold improvement of efficiency (0.44%) in fabricated NC/C 60 bilayer device [101]. Furthermore, an improvement in the EQE of 35% in the visible range and 5% EQE in the infrared regime was also observed.…”