In photodetection, the response time is mainly controlled by the device architecture and electron/hole mobility, while the absorption coefficient and the effective separation of the electrons/holes are the key parameters for high responsivity. Here, we report an approach toward the fast and highly responsive infrared photodetection using an n-type SnSe2 thin film on a p-Si(100) substrate keeping the overall performance of the device. The I–V characteristics of the device show a rectification ratio of ∼147 at ±5 V and enhanced optoelectronic properties under 1064 nm radiation. The responsivity is 0.12 A/W at 5 V, and the response/recovery time constants were estimated as ∼57 ± 25/34 ± 15 μs, respectively. Overall, the response times are shown to be controlled by the mobility of the constituent semiconductors of a photodiode. Further, our findings suggest that n-SnSe2 can be integrated with well-established Si technology with enhanced optoelectronic properties and also pave the way in the design of fast response photodetectors for other wavelengths as well.

An extrinsic approach toward achieving fast response and self‐powered photodetector is reported. It is shown that an organic–inorganic hybrid device (SnSe2/PEDOT:PSS) not only operates in self‐powered mode for infra‐red photodetection but also improves the response time with respect to inorganic (SnSe2) linear devices. Fast response and recovery time constants of ≈1.33 and 1.22 s, respectively, are obtained. Furthermore, the sensitivity is highest at zero bias and the device is stable for over 6 months stored in open air condition. The observed photo‐current, faster response and recovery time constants are ascribed to the formation of a strong built‐in electric field at the interface between SnSe2 and PEDOT:PSS. In a broader view of these findings, the device proves its potential as a self‐powered photo‐detector and the results reported here can pave the way to design self‐powered and fast response for other wavelengths.

InN epilayer has been grown by plasma-assisted molecular beam epitaxy on the AlN/n-Si (111) substrate. The self-powered photodetection has been carried out with an infra-red (IR) laser (λ=1550nm, power density ∼106.2mA/cm2), where a photoresponsivity was observed to be 3.36 μA/W with response times in milliseconds from the InN/AlN/n-Si (111)-based semiconductor–insulator–semiconductor (SIS) interface. Furthermore, to elucidate the vertical electrical transport properties of the SIS interface, low-temperature electrical behavior has been investigated over a range of 100–400 K. Experimental studies revealed an abnormal increase in the barrier height and a decrease in the ideality factor with increasing temperature, suggesting inhomogeneous barrier heights across the heterojunctions. Such inhomogeneity behaviors have been successfully explained on the basis of thermionic emission theory, assuming the existence of a double Gaussian distribution of barrier heights at the heterostructure interface. Moreover, the SIS device structure exhibits mean barrier heights (φ¯b0) of 1.11 and 0.63 eV, respectively, in two temperature regimes, indicating the presence of defect states and inhomogeneity at the interface, which is supported by the nonlinear behavior of the photocurrent with the power density.

We report detailed structural, electrical transport and IR photoresponse properties of large area VO2(M1) thin films deposited by a simple cost-effective two-step technique.

Humidity monitoring has become extremely vital in various technological fields such as environment control, biomedical engineering, and so on. therefore, a substantial interest lies in the development of fast and highly sensitive devices with high figures of merit. Self-powered and ultrasensitive humidity sensors based on SnS 2 nanofilms of different film thicknesses have been demonstrated in this work. The sensing behavior has been investigated in the relative humidity (RH) range of 2-99%. The observed results reveal a remarkable response and ultrafast detection even with zero applied bias (self-powered mode), with response and recovery times of ~ 10 and ~ 0.7 s, respectively. The self-powered behavior has been attributed to the inhomogeneities and the asymmetry in the contact electrodes. The highest sensitivity of ~ 5.64 × 10 6 % can be achieved at an applied bias of 5 V. This approach of fabricating such highly responsive, self-powered and ultrafast sensors with simple device architectures will be useful for designing futuristic sensing devices.

No abstract

No abstract

No abstract