All‐Inorganic CsPbBr<sub>3</sub> Perovskite Nanocrystals/2D Non‐Layered Cadmium Sulfide Selenide for High‐Performance Photodetectors by Energy Band Alignment Engineering

et al. 2022

Nanoscale Horiz.

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A high-responsivity CsPbBr₃ nanowire photodetector induced by CdS@Cd_xZn_1−xS gradient-alloyed quantum dots

Wei

et al. 2022

Nanoscale Horiz.

“…The device shows a rise and fall duration of 730 and 620 µs, respectively (Figure 3f), comparable with other fast photoresponse of 2D materials reported previously. [42][43][44][45][46][47][48][49] Next, we study the enhancement on the photovoltaic effect by ferroelectric polarization. It has been demonstrated that α-In 2 Se 3 is a ferroelectric n-type semiconductor with a strong coupling effect between resistance and ferroelectric polarization.…”

Section: Resultsmentioning

confidence: 99%

A Ferroelectric p–i–n Heterostructure for Highly Enhanced Short‐Circuit Current Density and Self‐Powered Photodetection

Yan

Wang

et al. 2022

Adv Elect Materials

Abstract2D‐layered materials and van der Waals heterostructures (vdWHs) have attracted intense interests in optoelectronic applications. However, the performance of photovoltaic effect based on vdWHs is still unsatisfactory, which is subjected to many factors, including settled small built‐in potentials and low light absorptions. Here, a pronounced photovoltaic effect is reported in MoTe2/(C4H9NH3)2(CH3NH3)2Pb3I10/α‐In2Se3 ferroelectric p–i–n vdWHs. An all‐dry transfer method held in an inert environment is utilized to ensure a good materials’ stability and high interfacial quality. The short‐circuit current density can increase three orders to 38 mA cm−2 by introducing perovskite; hence, the device works as a sensitive self‐powered photodetector with a photo on/off ratio of 2.4 × 105, a detectivity of 1.2 × 1012 Jones, and response times of 730 µs/620 µs. Moreover, the short‐circuit current density increases more than 25 times by enhancing the built‐in potential through programming the ferroelectric polarization of α‐In2Se3. In total, short‐circuit current density as high as 468 mA cm−2 is reached, which is one‐to‐two orders higher than that of typical lateral vdWHs. This work demonstrates the potential of high‐performance optoelectronic devices based on ferroelectric van der Waals p–i–n heterostructures.

“…To study the energy level alignment of the PbSe/ZnO heterostructure, we first employed UPS measurements (Figure S11a–c). The work function (WF) is expressed as: WF = h ν – E onset , , where h ν is the incident photon energy of 21.22 eV and E onset stands for the onset level of the UPS spectra. Thus, the energy of Femi level ( E F ) and the difference between E F and valence band maximum ( E VBM ) can be calculated to be 4.71 and 0.82 eV, respectively (Figure S11b,c).…”

Section: Resultsmentioning

confidence: 99%

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

Peng

ACS Appl. Mater. Interfaces

et al. 2021

Self Cite

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.