High-performance visible light photodetectors based on inorganic CZT and InCZT single crystals

Abstract

Herein, the optoelectrical investigation of cadmium zinc telluride (CZT) and indium (In) doped CZT (InCZT) single crystals-based photodetectors have been demonstrated. The grown crystals were configured into photodetector devices and recorded the current-voltage ( I-V ) and current-time ( I-t ) characteristics under different illumination intensities. It has been observed that the photocurrent generation mechanism in both photodetector devices is dominantly driven by a photogating effect. The CZT photodetector exhibits stable and reversible device performances to 632 nm light, including a promotable responsivity of 0.38 AW −1 , a high photoswitch ratio of 152, specific detectivity of 6.30 × 10 11 Jones, and fast switching time (rise time of 210 ms and decay time of 150 ms). When doped with In, the responsivity of device increases to 0.50 AW −1 , photoswitch ratio decrease to 10, specific detectivity decrease to 1.80 × 10 11 Jones, rise time decrease to 140 ms and decay time increase to 200 ms. Moreover, these devices show a very high external quantum efficiency of 200% for CZT and 250% for InCZT. These results demonstrate that the CZT based crystals have great potential for visible light photodetector applications.

A Sensitive Visible Light Photodetector Using Cobalt-Doped Zinc Ferrite Oxide Thin Films

“…It has been reported that at this certain bias voltage, all photogenerated carriers start to participate in photocurrent. 32 In this work, no free carriers are left to participate in photocurrent beyond −4 V at a light intensity of 17.9 W/m 2 .…”

“…The external quantum efficiency (EQE), responsivity, and sensitivity values of the devices with various post-annealing temperatures for 5 at % Co-doped ZnFe 2 O 4 thin film deposition are shown in Figure b. The responsivity ( R ) and EQE are calculated by eqs and where I ph is the photocurrent, P is the light power intensity, A is the effective area of the device, and T is the transmission of the oxide thin films. Sensitivity is another crucial characteristic of a photodetector, which is related to the signal-to-noise ratio.…”

Photosensitive activity of fabricated core-shell composite nanostructured p-CuO@CuS/n-Si diode for photodetection applications

“…The quantum efficiency is an additional factor used to analyse the performance of the device. The can be defined as the fraction of incident photons which contribute to the external photocurrent [ [56] , [57] , [58] ]. here h is plank constant, c is light speed, R is responsivity, q is electron charge and is used light wavelength.…”

High-Performance Flexible Ultraviolet Photodetectors Based on Facilely Synthesized Ecofriendly ZnAl:LDH Nanosheets

“…A detailed mechanism for this effect is discussed later in this section. The photoresponsivity (R) and specific detectivity (D*) of the PDs under various UV intensities (λ = 365 nm, V bias = 1 V) are calculated using eqs and , where Δ I = I light – I dark ; I dark and I light are the measured PD currents under dark and illuminated conditions, respectively, P 0 is the power of the incident light, A is the active area of the device, and q is the elementary charge. The results of these calculations are presented in Figure c,d.…”