Inorganic-ligand exchanging time effect in PbS quantum dot solar cell

Abstract

We investigate time-dependent inorganic ligand exchanging effect and photovoltaic performance of lead sulfide (PbS) nanocrystal films. With optimal processing time, volume shrinkage induced by residual oleic acid of the PbS colloidal quantum dot (CQD) was minimized and a crack-free film was obtained with improved flatness. Furthermore, sufficient surface passivation significantly increased the packing density by replacing from long oleic acid to a short iodide molecule. It thus facilities exciton dissociation via enhanced charge carrier transport in PbS CQD films, resulting in the improved power conversion efficiency from 3.39% to 6.62%. We also found that excess iodine ions on the PbS surface rather hinder high photovoltaic performance of the CQD solar cell.

Chemically encoded self-organized quantum chain supracrystals with exceptional charge and ion transport properties

“…S1), which demonstrate enhanced necking and electronic coupling from long-range ordered QC superstructures. 5,6 Typical PbS rock-salt cubic crystalline structure 45 was determined by characteristic X-ray diffraction (XRD) patterns and, as indexed in Fig. 1c, the attachment of these constituted QDs were found preferentially along the <100> axis with more than microns length scales (inset of Fig.…”

“…Nanostructured materials lie at the forefront of the state of the art energy conversion and storage technologies because of their excellent mechanical and electrical properties. [1][2][3][4][5][6][7][8] Spontaneous assembly small building blocks into superstructures with distinct functionality are scientific challenges in fundamental science (e.g., the origin of life) and nanotechnologies. [9][10][11][12] Elaborately self-organized superstructures from low-dimensional materials could dramatically improve their optical-electrical properties as well as providing new collective phenomena through long-range ordered interparticle cross-linking.…”

Molecular Doping of the Hole-Transporting Layer for Efficient, Single-Step-Deposited Colloidal Quantum Dot Photovoltaics

“…36 We optimized the soaking time based on previous ACN-based ligand exchanges of oleic-acid capped CQDs in device architectures employing EDT-PbS CQD as the HTL, 4, 6, 8-10, 14, 25, 27 where 30-60 s of soaking time leads to a complete ligand exchange. 37 Schematic 1. (a) Solar cell architecture employing a MAPbI3-PbS CQD absorber layer obtained via a single-step deposition.…”

Quantum Dots for Hybrid Energy Harvesting: From Integration to Piezo‐Phototronics

“…Mechanisms of the piezotronics and piezo‐phototronics are explained, which is followed by theoretical studies and demonstration of the device applications. For all hybrid energy harvesting applications, we particularly focus on colloidal QDs as they possess fascinating material properties for solar energy harvesting, such as (1) bandgap tunability by engineering the size of nanocrystals, (2) high absorption coefficient, and (3) solution processability, enabling facile material deposition technique as shown in Figure , which is universal phenomena for various kinds of QDs, for example Cd‐based, Pb‐based, and recently developed perovskite QDs …”