Amorphous ZnO/PbS Quantum Dots Heterojunction for Efficient Responsivity Broadband Photodetectors

Abstract

The integration of lead sulfide quantum dots (QDs) with a high-conductivity material that is compatible with a scalable fabrication is an important route for the applications of QD-based photodetectors. Herein, we first developed a broadband photodetector by combining amorphous ZnO and PbS QDs, forming a heterojunction structure. The photodetector showed detectivity up to 7.9 × 1012 and 4.1 × 1011 jones under 640 and 1310 nm illumination, respectively. The role of the oxygen background pressure in the electronic structure of ZnO films grown by pulsed laser deposition was systematically studied, and it was found to play an important role in the conductivity associated with the variation of the oxygen vacancy concentration. By increasing the oxygen vacancy concentration, the electron mobility of amorphous ZnO layers dramatically increased and the work function decreased, which were beneficial for the photocurrent enhancement of ZnO/PbS QD photodetectors. Our results provide a simple and highly scalable approach to develop broadband photodetectors with high performance.

Photodetecting properties of single CuO–ZnO core–shell nanowires with p–n radial heterojunction

“…Additionally, it is a relatively abundant and non-toxic material with a broad family of morphologies for its easy to prepare nanostructures (nanowires, nanotubes, rods, nanofibers, nanoflowers, etc.) 30 – 34 , finding applications in electronic devices 35 , sensors 36 , photodetectors 37 , solar cells 38 , photocatalysis 39 etc. By combining the two materials, CuO and ZnO, into a radial core–shell architecture as CuO–ZnO nanowires, a type II band alignment is obtained between the two semiconductors.…”

A stretchable ultraviolet-to-NIR broad spectral photodetector using organic–inorganic vertical multiheterojunctions

“…Zinc oxide (ZnO) is emerging as a potential candidate material for the development of UV PDs. [26][27][28] Several approaches to broaden the absorption spectra of ZnO-based PDs from UV to a wider range have been reported, including synthesizing a pristine ZnO honeycomb nanostructure, 29 doping Cu impurities in ZnO NWs, 30 combining amorphous ZnO and PbS QDs, 31 using ZnO NW array/PbS QDs heterostructures, 3 and using ZnO/perovskite heterojunctions. 32 Most ZnO-based broadband PDs are formed using a rigid and inflexible form factor.…”

Embedding PbS quantum dots in MAPbCl0.5Br2.5 perovskite single crystal for near‐infrared detection

“…In this work, QDs were successfully synthesized via a rapid hot injection method by following a reported procedure that uses hexamethyldisilathiane (TMS) as a sulfur precursor. 6,26 PbS QDs were successfully embedded in MAPbCl 0.5 Br 2.5 single crystal by solution-processed epitaxial growth. [27][28][29][30] Typically, the intrinsic material properties and optoelectronic properties of the MAPbCl 0.5 Br 2.5 with PbS QDs composite crystals were investigated.…”

“…In this work, QDs were successfully synthesized via a rapid hot injection method by following a reported procedure that uses hexamethyldisilathiane (TMS) as a sulfur precursor 6,26 . PbS QDs were successfully embedded in MAPbCl 0.5 Br 2.5 single crystal by solution‐processed epitaxial growth 27–30 .…”