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

Abstract

Ternary silver bismuth sulfide (AgBiS 2) colloidal nanocrystals (NCs) have been recognized as a photovoltaic absorber for environmentally-friendly and lowtemperature-processed thin film solar cells. However, previous synthetic methods involving hot injection of sulfur precursors into metal oleate precursor solutions do not provide a balance between nucleation and growth, leading to AgBiS 2 NCs with broad size distributions. Here, we demonstrate the modified synthetic route that size distribution of AgBiS 2 NCs can be improved by pre-adding the non-coordinating 1-octadecene (ODE) solvent into metal precursor solutions, leading to controlled concentration of coordinating oleic acid with improved hot-injection synthetic conditions. The addition of ODE as a non-coordinating solvent to metal precursor/oleic acid solution significantly suppresses variations in the concentration of coordinating oleic acid after injection of the sulfur precursor solution, leading to a homogenous reaction between the metal and sulfur precursors. For photovoltaic devices fabricated using the resultant AgBiS 2 NCs, the champion device shows power conversion efficiency (PCE) of 5.94% with an open-circuit voltage (V OC) of 0.52 V. This performance is better than that a control device (PCE of 5.50% and V OC of 0.49 V) because of the reduced energetic disorder and band tail broadening originating from the uniformly-sized AgBiS 2 NCs.

Improved Eco-Friendly Photovoltaics Based on Stabilized AgBiS2 Nanocrystal Inks

“…Oleate-capped AgBiS 2 NCs were synthesized using previously reported methods. 34 Oleate-capped AgBiS 2 NC solution (3 mL) dispersed in octane (6 mg mL −1 ) was added to 3 mL of AgI and/or BiI 3 halometallates (total 0.3 mmol) and MAI (0.3 mmol) in DMF solution. These were mixed vigorously for 90 s, and centrifugation was performed for 1 min for clear phase separation.…”

Design of Ag Injection in Bi2S3 (AgBiS2) Thin Films for Photoelectrochemical Cell and Solar Cell Applications

“…Solar performance of the present result is compared with previous reports and is given in table 6. From the table 6, it is noted that the device FTO/ AgBiS 2 /CdS/Ag has higher e ciency than that of AgBiS 2 /PTB7 [56], AgBiS 2 QDSSC [9], ITO/ZnO/AgBiS 2 /P3HT/MoO 3 /Al [17] devices whereas slightly lower than ITO/ZnO/AgBiS 2 /P3HT/Au [37] and ITO/ZnO/ AgBiS 2 /PTB7/MoO 3 /Ag [11,12] devices. By comparing with higher performance devices, the present study used AgBiS 2 coated on FTO as 'p' layer, CdS as 'n' layer and Ag metallic contact whereas in the previous investigations, the authors had used polymer layer for conducting enhancement, window layer for avoiding the loss of incident photons and Mo as metallic contact.…”

“…The latter one is of interest because it has potential applications in different elds such as photovoltaics and thermoelectric devices etc [7][8][9][10]. For instance, ITO/ZnO/AgBiS 2 /PTB7/MoO/Ag devices fabricated by J. T. Oh et al, (2020) [11] and I. B.…”

Mixed AgBiS2 nanocrystals for photovoltaics and photodetectors

“…In the past few years there has been a remarkable progress in the synthesis and application of colloidal AgBiS 2 nanocrystals as the photoactive material in solar cell devices. 7,11,12,[17][18][19][20][21][22][23]24 The low carrier diffusion length and the non-negligible recombination pathways have been identified as the main limiting factors for photocurrent generation, especially when using thick active layers. 7,12 Therefore, the record solar cell efficiencies reported so far typically limit the optimal AgBiS 2 layer thickness at around 35 nm.…”