High Performances for Solution‐Pocessed 0D–0D Heterojunction Phototransistors

Abstract

All‐inorganic cesium lead halide perovskite nanocrystals have emerged as attractive optoelectronic nanomaterials due to their stabilities and highly efficient photoluminescence. High‐sensitivity photodetection covering a large spectral range from ultraviolet to near‐infrared is dominated by phototransistors. To overcome existing limitations in sensitivity and cost of state‐of‐the‐art systems, new‐style device structures and composite material systems are needed with low‐cost fabrication and high performance. Here, field‐effect phototransistors (FEpTs) based on CsPbBr3–PbS colloidal quantum dot heterostructure dominate to obtain a wide response spectral range and high performance. The large spectral detection spectrum is from 400 to 1500 nm similar to PbS quantum dots' response. It is worth mentioning that the device shows responsivity up to 4.5 × 105 A W−1, which is three orders of magnitude higher than the counterpart of individual material‐based devices. Furthermore, other high performance of hybrid CsPbBr3–PbS FEpTs including a short photoresponse time (less than 10 ms) is ascribed to the assistance of heterojunction on the transfer of photoexcitons. The solution‐based fabrication process and excellent device performance strongly underscore CsPbBr3–PbS quantum dot as a promising material for future photoelectronic applications.

Engineering Vacancies in Bi2S3yielding Sub‐Bandgap Photoresponse and Highly Sensitive Short‐Wave Infrared Photodetectors

“…2D Bi 2 S 3 nanosheets and colloidal quantum dots (CQDs) have also been developed . Although photodetectors based on Bi 2 S 3 nanomaterials have been reported, their performance is lower than commercial silicon detectors and recent‐emerging material platforms such as 2D materials, perovskite, and QD‐based hybrid photodetectors . For example, the Bi 2 S 3 nanorods and nanoflowers showed a photo‐switching ratio of only 23.6 .…”

Self-powered lead-free quantum dot plasmonic phototransistor with multi-wavelength response

“…This indicates that more electrons and photoexcitons can be excited with larger incident photo energy light at the short wavelength and contribute more to photocurrent. This also indicates that electrons have to overcome the Schottky barrier during transport [50]. Under the illumination of larger energy light at the shorter wavelength, the built-in potential of the Schottky barrier decreases, resulting in a large increase in the free carrier density, leading to easier carrier transport and tunneling and thus to greatly enhanced photocurrents.…”

A Fast Response−Recovery 3D Graphene Foam Humidity Sensor for User Interaction

“…We assure high quality humidity measurement in different ambient temperature operating conditions in climate chamber as shown in [26]. In order to measure the channel current flowing into the drain electrode ( I DS ) [27,28,29], the source (with ground connection) and drain electrodes were connected with a Keithley 2400 apparatus (Tektronix China Ltd, Shanghai, China). The electrical measurements were also performed with this system, and the RH of the environment was measured by a commercial humidometer.…”