Water-resistant AgBiS₂ colloidal nanocrystal solids for eco-friendly thin film photovoltaics

Abstract

The AgBiS2 nanocrystal solar cells exhibit no drop in their device performance before and after the water treatment, suggesting that AgBiS2 nanocrystal solids are highly water-resistant.

Improved size distribution of AgBiS 2 colloidal nanocrystals by optimized synthetic route enhances photovoltaic performance

“… 34 Elemental compositions were also confirmed by XPS that Modified method provides the resultant AgBiS 2 NCs with the higher amount of Ag element, indicating the average size reduction, better stoichiometry and energetically more stable surface termination, compared to those in Control method (Figure S5 and Table S1). 28,30,34 …”

“…34 Elemental compositions were also confirmed by XPS that Modified method provides the resultant AgBiS 2 NCs with the higher amount of Ag element, indicating the average size reduction, better stoichiometry and energetically more stable surface termination, compared to those in Control method ( Figure S5 and Table S1). 28,30,34 In addition, we increased the injection temperature of the sulfur precursor solution up to 130 C to identify the effect on the size-distribution of the AgBiS 2 NCs. HR-TEM images and size-distribution histograms showed that the overall size-distribution of AgBiS 2 NCs was improved with the Modified method because of the reduced variation in the concentration of oleic acid (see Figure S6).…”

“…28,29 In particular, the ligand binding sites and energies on NC surfaces vary according to the functional groups of the surface ligands, indicating that these groups undergo different ligand exchange mechanisms. 30 Although the use of oleylamine ligands can increase the monodispersity of AgBiS 2 NCs, the corresponding ligand exchange, which have been optimized for X-type-oleate-stabilized AgBiS 2 NCs, cannot be used directly for L-type-oleylaminecapped AgBiS 2 NCs due to the differences in stoichiometry and surface ligand binding. 28,29 Accordingly, a new synthetic protocol is needed to improve the monodispersity of AgBiS 2 NCs using only oleate ligands, thus avoiding changes in NC stoichiometry originating from the use of different surface ligands (ie, oleylamine).…”

“…Surface ligands with various functional groups such as thiol, amine, and carboxylate greatly affect the chemical and physical properties of the resultant semiconducting colloidal NCs 28,29 . In particular, the ligand binding sites and energies on NC surfaces vary according to the functional groups of the surface ligands, indicating that these groups undergo different ligand exchange mechanisms 30 . Although the use of oleylamine ligands can increase the monodispersity of AgBiS 2 NCs, the corresponding ligand exchange, which have been optimized for X‐type‐oleate‐stabilized AgBiS 2 NCs, cannot be used directly for L‐type‐oleylamine‐capped AgBiS 2 NCs due to the differences in stoichiometry and surface ligand binding 28,29 .…”

Near‐Infrared Photoactive Semiconductor Quantum Dots for Solar Cells

“…Subsequently, a number of Ag-Bi-S QDSCs emerge. [145][146][147] [41] Copyright 2016, Macmillan Publishers Ltd.…”