Enhanced Light Trapping in Conformal CuO/Si Microholes Array Heterojunction for Self-Powered Broadband Photodetection

Abstract

In this letter, we demonstrate the fabrication of a conformal CuO/Si microholes array heterojunction through the DC reactive magnetron sputtering from a high-purity Cu target. By using the monolayer graphene as the top electrode, the device served well as a self-powered vis-NIR photodetector, showing a high responsivity of 301.5 mA W −1 , specific detectivity of 7.96 × 10 12 Jones and a fast response speed (rise time 9.9µ s and fall time 10µs) upon 530 nm illumination. Compared to its planar counterpart, the responsivity was remarkably enhanced over the broadband region. The underlying reason should be ascribed to the improved light trapping in the microholes via the longitudinal Fabry-Perot (F-P) cavity resonance, according to theoretical simulation by finite-difference timedomain (FDTD) solution. Such an effect gave rise to an enhanced light-matter interaction, leading to the improved photoresponse. This work also opens up an effective way for the on-chip high performance photodetection due to the well compatibility with the current complementary metal-oxidesemiconductor (CMOS) technology. Index Terms-Fabry-Perot cavity resonance, light trapping, microholes array, broadband photodetection. I. INTRODUCTIONB ULK crystalline Si is a leading material for commercial visible light photodetectors due to its suitable bandgap (∼1.12 eV), high carrier mobility, long-term stability, abundant material resources and the mature Si-based semiconductor manufacturing techniques [1]. However, the optical reflection loss of crystalline Si in visible region is up to 40% due to its high reflective index, which seriously limits the efficiency Manuscript

Pronounced Optoelectronic Effect in n–n ReS2 Homostructure

“…The open-circuit voltage ( V OC ) and short-circuit current ( I SC ) variables were measured, as shown in Figure b ( V OC of near 0.15 V and I SC of 196 nA were measured at 365 nm). To examine the RR of our study under the V OC parameter, the result of the ReS 2 homostructure diode is displayed with other references in Figure c. ,,,− It shows that this work achieved significant value considering that our device is n–n homostructure. In addition, photoresponsivity ( R ) was calculated to examine the photodetecting performance of the ReS 2 photodiode.…”

“…(b) I SC and V OC under different illumination light sources while applying a 50 mW cm –2 power density and a 10 V gate voltage. (c) Rectification ratio and V OC comparison of various structures. ,,,− (d) Zoomed-in view of the I – V curves. I SC stands for short-circuit current, and V OC stands for open-circuit voltage.…”

Superior Performances of Self‐Driven Near‐Infrared Photodetectors Based on the SnTe:Si/Si Heterostructure Boosted by Bulk Photovoltaic Effect

“…Figure 4d presents the EQE of the SnTe:Si/Si and SnTe/Si devices measured at room temperature (300 K) as a function of light intensity for the 850 nm light. The EQE is defined as the ratio of the number of charge carriers collected by the device to the number of photons shining on the active area from the exterior laser: [ 36 ] $$\[ \begin{array}{*{20}{c}}{EQE\; = ({I_{{\rm{ph}}}}{\rm{/}}q){\rm{/}}\emptyset \; = ({I_{{\rm{ph}}}}{\rm{/}}q\;)\left( {h\nu {\rm{/}}{P_{{\rm{in}}}}} \right)}\end{array} \]$$where I ph, ∅, h , ν, and P in represent the photocurrent, number of incident photons, Planck's constant, frequency of the incident light, and incident light power on the active area of the device, [ 37 ] respectively. For the SnTe/Si device in Figure 4d, a maximum EQE of 75% is observed at a light intensity of 2.1 mW cm −2 .…”

“…where I ph, ∅, h, ν, and P in represent the photocurrent, number of incident photons, Planck's constant, frequency of the incident light, and incident light power on the active area of the device, [37] respectively. For the SnTe/Si device in Figure 4d, a maximum EQE of 75% is observed at a light intensity of 2.1 mW cm −2 .…”

Study of optical, structural and electrical properties of copper oxide films prepared by chemical bath deposition with laser at different concentrations

“…Kim et al reported on the fabrication of a fast ITO/CuO/Si photodetector [7]. Zhang et al prepared a conformal CuO/Si microholes array heterojunction through DC reactive magnetron sputtering with a maximum responsivity of 0.3 A/W at 530 nm [8]. Salih et al prepared a porous silicon/CuO silicon photodetector by electrochemical etching and pulsed laser deposition, with studying its main parameters [9].…”