Silver Bismuth Sulfoiodide Solar Cells: Tuning Optoelectronic Properties by Sulfide Modification for Enhanced Photovoltaic Performance

Abstract

Silver bismuth iodides are non-toxic and comparatively cheap photovoltaic materials, but their wide bandgaps and downshifted valence band edges limit their This article is protected by copyright. All rights reserved. performance as light absorbers in solar cells. Herein, we introduce a strategy to tune the optoelectronic properties of silver bismuth iodides by partial anionic substitution with the sulfide dianion. A consistent narrowing of the bandgap by 0.1 eV and an upshift of the valence band edge by 0.1-0.3 eV upon modification with sulfide are demonstrated for AgBiI 4 , Ag 2 BiI 5 , Ag 3 BiI 6 and AgBi 2 I 7 compositions. Solar cells based on silver bismuth sulfoiodides embedded into a mesoporous TiO 2 electron transporting scaffold, and a poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] hole transporting layer significantly outperform devices based on sulfide-free materials, mainly due to enhancements in the photocurrent by up to 48 %. A power conversion efficiency of 5.44 ± 0.07 % (J sc = 14.6 ± 0.1 mA cm -2 ; V oc = 569 ± 3 mV; fill factor = 65.7 ± 0.3 %) under 1 sun irradiation and stability under ambient conditions for over a month are demonstrated. The results reported herein indicate that further improvements should be possible with this new class of photovoltaic materials upon advances in the synthesis procedures and an increase in the level of sulfide anionic substitution.

The Impact of Cesium and Antimony Alloying on the Photovoltaic Properties of Silver Bismuth Iodide Compounds

“…[17][18][19] They exhibit direct bandgap energies below 2 eV, and optoelectronic properties of these compounds are favorable for application in solar cells. [18][19][20][21][22][23][24][25] To the best of our knowledge, there is little literature about SBI-based solar cells. For the first time in 2016, Kim et al used a solution-based method to prepare solar cells based on AgBi 2 I 7 .…”

“…[23] Pai et al used silver bismuth sulfoiodides with different concentrations as a light absorber in solar cells and achieved a PCE of 5.5%. [24] A two-step co-evaporation/annealing method for depositing SBI compositions was reported by Khazaee et al AgBiI 4 , AgBi 2 I 7 , and Ag 2 BiI 5 had a bandgap energy of 1.80, 1.83, and 1.90 eV, respectively, and they displayed the best PCE of 0.89% for AgBiI 4 -based solar cells. [25] In addition to the solar cell, SBI rudorffites also had other applications, such as near-IR (NIR)-blind visible-light photodetectors, and sensitive and stable X-ray detectors.…”

Lead‐Free Double Perovskites for Perovskite Solar Cells

“…The Ag–Bi–I family was further expanded with the incorporation of sulfide anions via solution process . The partial substitution of sulfide and changing levels of anionic substitution in Ag a Bi b I x led to tunable optoelectronic properties.…”

“…d2) Stability test of Ag 3 BiI 6−2 x S x ‐based PSCs with x = 0 and 4 at.% stored in air under light. Reproduced with permission . Copyright 2018, WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.…”

Organic sensitization of graphene oxide and reduced graphene oxide thin films for photovoltaic applications

“…3,4 Converting solar energy to electric energy requires the construction of cost-effective and efficient PV solar cells to fulfil the need for accessible clean energy exerting the minimum ecological flaws. 5,6 A prominent substitute for the expensive and conventional silicon PV cell is the organic PV (OPV) cell which is expected to exhibit a positive economic impact in terms of production. 7,8 The consumption of fossil fuels is increasing day by day with the increasing demand for energy.…”