Asymmetric semicircular and triangular electrode structures to increase photo-to-dark-current ratio in MgZnO metal semiconductor metal photodetectors

Abstract

The effects of asymmetric semicircular and asymmetric triangular Schottky barriers on the current-voltage (I-V) characteristics of MgZnO metal semiconductor metal (MSM) photodetectors (PDs) have been investigated using a two-dimensional (2D) physical model based on the driftdiffusion theory. At a bias of 5 V, compared with the symmetric rectangular Schottky barrier MgZnO MSM PD, the dark current of the asymmetric semicircular and triangular Schottky barrier MgZnO MSM PDs is reduced by a factor of 15 for each electrode structure. On the other hand, the photocurrents of these asymmetric semicircular and asymmetric triangular PDs are enhanced by factors of 1.2 and 2, respectively. On the basis of these I-V characteristics, the highest photo-to-dark-current ratio (PDR) of 7294 is achieved in the asymmetric triangular Schottky barrier MgZnO MSM PD. In addition, the PDR can be increased further by optimizations, such as the incorporation of different metals to provide a higher asymmetry. The results show that the design of the asymmetric semicircular and asymmetric triangular Schottky barriers on the MgZnO MSM PDs is a promising method for applications requiring a low power and a high PDR.

Enhancing the Photoelectric Performance of Photodetectors Based on Metal Oxide Semiconductors by Charge‐Carrier Engineering

“…A physical model based on band energy theory has been developed to illustrate the origin of the photoresponse at 0 V in this device, which demonstrates a new route to assembling self-powered PDs. By using a 2D physical model based on the drift-diffusion theory, Song et al investigated the influences of asymmetric semicircular and asymmetric triangular Schottky barriers on the photoelectric performance of MgZnO MSM PD [123] At 5 V, compared to the MgZnO MSM PD with symmetric rectangular Schottky barrier, the dark currents of the MgZnO MSM PDs with asymmetric semicircular and triangular Schottky barrier are reduced by a factor of 15 for each electrode structure, while the photocurrents are enhanced by factors of 1.2 and 2, respectively. The highest on/off ratio of 7294 is achieved in the MgZnO MSM PD with asymmetric triangular Schottky barrier at a bias of 5 V under 260 nm light illumination with a power of 0.4 µW.…”

A flexible and miniaturized hair dye based photodetector via chemiluminescence pathway

“…Optical chemical sensors possess high sensitivity, easy operation, high accuracy, and wide detection capacity. (Ratterman et al, 2014;Salama et al, 2007;Hatakeyama et al, 2009;Wang et al, 2015;Yamamoto et al, 2013;Ruano et al, 2000;Tsafack et al, 2000;Ivanov et al, 2001;Askari et al, 2002;Song et al, 2005) In particular, luminescence-based optical chemical sensors exhibit certain advantages, including a low detection limit, insensitivity to electrical disturbance, and a wide linear working range. (Delaney et al, 2011;Borisov et al, 2008).…”

“…Naderi and Hashim, 2012;Carturan et al, 2015;Li et al, 2014., Mohite andRajpure, 2014;Lv et al, 2013;Song et al, 2015;Kim and Lee, 2013;Masouleh et al, 2015) Flexibility is crucial for electronic device integration and has major implications. In devices, concave and convex bending modes allow access to some otherwise unachievable performance properties.…”