A colloidal quantum dot infrared photodetector and its use for intraband detection

Abstract

Wavefunction engineering using intraband transition is the most versatile strategy for the design of infrared devices. To date, this strategy is nevertheless limited to epitaxially grown semiconductors, which lead to prohibitive costs for many applications. Meanwhile, colloidal nanocrystals have gained a high level of maturity from a material perspective and now achieve a broad spectral tunability. Here, we demonstrate that the energy landscape of quantum well and quantum dot infrared photodetectors can be mimicked from a mixture of mercury selenide and mercury telluride nanocrystals. This metamaterial combines intraband absorption with enhanced transport properties (i.e. low dark current, fast time response and large thermal activation energy). We also integrate this material into a photodiode with the highest infrared detection performances reported for an intraband-based nanocrystal device. This work demonstrates that the concept of wavefunction engineering at the device scale can now be applied for the design of complex colloidal nanocrystal-based devices.

Designing Photovoltaic Devices Using HgTe Nanocrystals for Short and Mid‐Wave Infrared Detection

“…f) Photocurrent spectra measured at 80 K under 0 and 1 V bias, showing photoresponse coming from the HgSe intraband absorption (green), HgTe transport matrix (brown), and HgTe barrier (orange). Adapted under the terms of a Creative Commons Attribution 4.0 International License . Copyright 2019, The Authors, published by Springer Nature Publishing AG.…”

“…Arrays of mercury selenide (HgSe) nanocrystals show intraband contribution, however, suffer from a slow response, a low activation energy (i.e., cooling barely improves performance), and a large dark current. These issues can be solved either by growing a HgTe shell around the HgSe‐absorbing material or by mixing HgSe and HgTe nanocrystals . The strategy behind these approaches is to uncouple absorption from transport.…”

Ultrahigh Infrared Photoresponse in Titanium Sesquioxide at Mott‐Insulator Transition

“…Moreover, unique surface and interface properties and high conductivities also opened up their prospects to develop quantum devices. [ 1–6 ] The small effective mass is associated with a small gap. For example, GaAs, InAs, and InSb with bandgaps of roughly 1.43, 0.36, and 0.18 eV, respectively, have the conduction band effective masses of 0.065, 0.025, and 0.014, respectively, at room temperature.…”

Flexible and efficient perovskite quantum dot solar cells via hybrid interfacial architecture

“…Colloidal quantum dots (QDs) have received remarkable research attention due to their excellent properties such as tuneable bandgaps, multiple exciton effects and excellent stability [1][2][3][4][5][6][7][8] . These unique features facilitate their wide applications in optoelectronic devices such as photodetectors, [9][10][11][12] light emitting diodes [13][14] and photovoltaics [15][16][17] . Solution-processed QDs have demonstrated their strong potential for high-e ciency and low-cost photovoltaics.…”