TY - JOUR
T1 - Fast Near-Infrared Photodetectors Based on Nontoxic and Solution-Processable AgBiS2
AU - Huang, Yi Teng
AU - Nodari, Davide
AU - Furlan, Francesco
AU - Zhang, Youcheng
AU - Rusu, Marin
AU - Dai, Linjie
AU - Andaji-Garmaroudi, Zahra
AU - Darvill, Daniel
AU - Guo, Xiaoyu
AU - Rimmele, Martina
AU - Unold, Thomas
AU - Heeney, Martin
AU - Stranks, Samuel D.
AU - Sirringhaus, Henning
AU - Rao, Akshay
AU - Gasparini, Nicola
AU - Hoye, Robert L.Z.
N1 - Publisher Copyright:
© 2023 The Authors. Small published by Wiley-VCH GmbH.
PY - 2023
Y1 - 2023
N2 - Solution-processable near-infrared (NIR) photodetectors are urgently needed for a wide range of next-generation electronics, including sensors, optical communications and bioimaging. However, it is rare to find photodetectors with >300 kHz cut-off frequencies, especially in the NIR region, and many of the emerging inorganic materials explored are comprised of toxic elements, such as lead. Herein, solution-processed AgBiS2 photodetectors with high cut-off frequencies under both white light (>1 MHz) and NIR (approaching 500 kHz) illumination are developed. These high cut-off frequencies are due to the short transit distances of charge-carriers in the ultrathin photoactive layer of AgBiS2 photodetectors, which arise from the strong light absorption of this material, such that film thicknesses well below 120 nm are sufficient to absorb >65% of NIR to visible light. It is also revealed that ion migration plays a critical role in the photo-response speed of these devices, and its detrimental effects can be mitigated by finely tuning the thickness of the photoactive layer, which is important for achieving low dark current densities as well. These outstanding characteristics enable the realization of air-stable, real-time heartbeat sensors based on NIR AgBiS2 photodetectors, which strongly motivates their future integration in high-throughput systems.
AB - Solution-processable near-infrared (NIR) photodetectors are urgently needed for a wide range of next-generation electronics, including sensors, optical communications and bioimaging. However, it is rare to find photodetectors with >300 kHz cut-off frequencies, especially in the NIR region, and many of the emerging inorganic materials explored are comprised of toxic elements, such as lead. Herein, solution-processed AgBiS2 photodetectors with high cut-off frequencies under both white light (>1 MHz) and NIR (approaching 500 kHz) illumination are developed. These high cut-off frequencies are due to the short transit distances of charge-carriers in the ultrathin photoactive layer of AgBiS2 photodetectors, which arise from the strong light absorption of this material, such that film thicknesses well below 120 nm are sufficient to absorb >65% of NIR to visible light. It is also revealed that ion migration plays a critical role in the photo-response speed of these devices, and its detrimental effects can be mitigated by finely tuning the thickness of the photoactive layer, which is important for achieving low dark current densities as well. These outstanding characteristics enable the realization of air-stable, real-time heartbeat sensors based on NIR AgBiS2 photodetectors, which strongly motivates their future integration in high-throughput systems.
KW - AgBiS
KW - cut-off frequency
KW - heart-beat sensors
KW - near-infrared photodetectors
KW - solution-processable electronics
KW - ultrathin absorbers
UR - http://www.scopus.com/inward/record.url?scp=85178954380&partnerID=8YFLogxK
U2 - 10.1002/smll.202310199
DO - 10.1002/smll.202310199
M3 - Article
C2 - 38063859
AN - SCOPUS:85178954380
SN - 1613-6810
VL - 20
JO - Small
JF - Small
IS - 18
M1 - 2310199
ER -