Room-Temperature Direct Synthesis of PbSe Quantum Dot Inks for High-Detectivity Near-Infrared Photodetectors

Abstract

A PbSe colloidal quantum dot (QD) is typically a solution-processed semiconductor for near-infrared (NIR) optoelectronic applications. However, the wide application of PbSe QDs has been restricted due to their instability, which requires tedious synthesis and complicated treatments before being applied in devices. Here, we demonstrate efficient NIR photodetectors based on the room-temperature, direct synthesis of semiconducting PbSe QD inks. The in-situ passivation and the avoidance of ligand exchange endow PbSe QD photodetectors with high efficiency and low cost. By further constructing the PbSe QDs/ ZnO heterostructure, the photodetectors exhibit the NIR responsivity up to 970 mA/W and a detectivity of 1.86 × 10 11 Jones at 808 nm. The obtained performance is comparable to that of the state-of-the-art PbSe QD photodetectors using a complex ligand exchange strategy. Our work may pave a new way for fabricating efficient and low-cost colloidal QD photodetectors.

Highly Responsive Mid-Infrared Metamaterial Enhanced Heterostructure Photodetector Formed out of Sintered PbSe/PbS Colloidal Quantum Dots

“…The formation of a heterostructure is thus important for obtaining photogain. Various accounts on the increase of responsivities due to the presence of a heterojunction have already been given for such planar configurations. ,− Indication for the presence of a heterojunction between the PbSe and PbS can be derived from Figure c. The figure shows the dark current between the Au electrodes for a PbSe layer stack (brown and red).…”

One-step synthesized PbSe nanocrystal inks decorated 2D MoS2 heterostructure for high stability photodetectors with photoresponse extending to near-infrared region

“…It clearly shows that the photocurrents increase with the increase in the incident light intensity from 20.8 μW cm −2 to 51.6 mW cm −2 . As we know, the responsivity ( R ) and detectivity ( D *) are two key parameters to evaluate the optoelectronic performance of the photodetector, which can be expressed as the following equations: 31,39–41 R = I ph /( P.S )Where A and B are the effective illumination area of the device and bandwidth in HZ, and i N is the noise current spectra density at the bandwidth of 1 HZ in dark conditions. We first tested the time-resolved dark current at a bias of 3 V, and then the noise power density can be obtained by taking a Fourier transform of the dark current curves.…”

Recent Progress of Flexible Photodetectors Based on Low‐Dimensional II–VI Semiconductors and Their Application in Wearable Electronics

“…However, this strategy will inevitably lead to inconsistent ligand exchange and surface damages during the repeated cycles of surface ligands exchange steps by using organic polar solvent, which will also deteriorate the optoelectronic performance of the QDs based photodetectors. [76,77] Up to now, an optimized ligands exchange method has been explored to minimize the surface damage by directly synthesize semiconductor PbX (X = S and Se) QDsinks at room temperature, [78,79] but it has not been dem onstrated in II-VI semiconductor QDs system. We deem that this strategy may provide a better alternative for the synthesis of II-VI semiconductors QDs in future research.…”