High-response hybrid quantum dots- 2D conductor phototransistors: recent progress and perspectives

Abstract

Abstract:Having been inspired by the tremendous progress in material nanoscience and device nanoengineering, hybrid phototransistors combine solution processed colloidal semiconductor quantum dots (QDs) with graphene or two-dimensional (2D) semiconductor materials. Novel detectors demonstrate ultrahigh photoconductive gain, high and selective photoresponse, low noise, and very high responsivity in visible-and near-infrared ranges. The outstanding performance of phototransistors is primarily due to the strong, selective, and size tunable absorption of QDs and fast charge transfer in 2D high mobility conductors. However, the relatively small mobility of QD nanomaterials was a technological barrier, which limited the operating rate of devices. Very recent innovations in detector design and significant progress in QD ligand engineering provide effective tools for further qualitative improvements. This article reviews the recent progress in material science, nanophysics, and device engineering related to hybrid phototransistors. Detectors based on various QD nanomaterials and several 2D conductors are compared, and advantages and disadvantages of various nanomaterials for applications in hybrid phototransistors are identified. We also benchmark the experimental characteristics with model results that establish interrelations and tradeoffs between detector characteristics, such as responsivity, dark and noise currents, the photocarrier lifetime, response, and noise bandwidths. We have shown that the most recent phototransistors demonstrate performance limited by the fundamental generation recombination noise in high gain devices. Interrelation between the dynamic range of the detector and the detector sensitivity is discussed. The review is concluded with a brief discussion of the remaining challenges and possible significant improvements in the performance of hybrid phototransistors.

Synthesis, structure and photoelectric properties of selenide composites with in situ constructed Sb2Se3/NaSbSe2 heterojunction

“…S8, Supporting Information). This slow decay could be associated with the presence of charge trap centers and other defect states in composites, as already found in previous reports [67][68][69]. The photoresponse has not significant difference during at least 10 cycles, revealing the excellent stability of the selenide composites with internal heterojunctions.…”

Nanoprinted Quantum Dot–Graphene Photodetectors

“…In general, sectors such as telecommunication and medicine would benefit from the reduced costs as well. The next generation of IR semiconductor‐photodetectors could be based on the synergistic combination of graphene field‐effect transistors (GFET) for signal amplification and IR‐sensitive colloidal quantum dots (QD) for light harvesting . Such QD/GFET detectors benefit from inexpensive solution‐processed QD synthesis, complementary metal‐oxide‐semiconductor compatibility, and room‐temperature operation with extraordinary responsivities and specific detectivities of 10 9 A W −1 and 10 13 Jones, respectively, in the UV, vis, and NIR spectral ranges .…”

Narrow‐Band QD‐Enhanced PIN Metal‐Oxide Heterostructure Phototransistor with the Assistance of Printing Processes

“…2020, 8,1901472 can be determined from the above noise current spectrum. The detectivity is given by the following [38,39] NEP w Hz NEP cmHz w ,Jones…”

“…It characterizes the sensor relative to its noise, which can be determined from the above noise current spectrum. The detectivity is given by the following where NEP is the noise‐equivalent power, A is the active area, I N is the noise current density, and R is the responsivity.…”