Fabrication and Photosensitivity of CdS/Silicon Nanoscrew Photoresistor

Abstract

Silicon nanoscrews with aspect ratio of 3, 6 and 9 corresponding to 4, 8 and 12 etching cycles are fabricated by CsCl selfassembly lithography and inductively coupled plasma (ICP) dry etching with "Bosch Process", which can reduce the reflection to below to 10% for wavelength from 400 to 1000 nm. A layer of Cadmium sulfide (CdS) film covers onto the silicon nanoscrews surface to photoresistor. The XRD pattern shows the CdS packed both on the nanoscrew and planar surface are well-crystallized. The nanoscrew substrate with the large surface ratio can increase the light absorption and quantity of sensitive material, which can improve the photosensitivity of the CdS photoresistor compared to the planar one obviously. However, the aspect ratio of nanoscrew is not the larger the better for that the high aspect ratio also increases the difficulty of CdS package. The photosensitivity response test results show that the nanoscrew photoresistor with 6 aspect ratio has the best performance under different illumination. With 10000 mW/cm 2 , the best photosensitivity response achieves to 141 for nanoscrew sample.

Fabrication of CdS Nanorods on Si Pyramid Surface for Photosensitive Application

“…In our previous work, we have covered 200 nm thickness CdS film on silica planar, silica pillar, and Si nanoscrew structure surfaces through radio frequency (RF) magnetron sputtering, which has the photosensitivity response of 62, 137, and 141 respectively. In this paper, the CdS nanorods on the Si pyramid structure, which is fabricated by the hydrothermal reaction, are used for photosensitive applications for the first time.…”

“…In our previous work, we have covered 200 nm thickness CdS film on silica planar, 24 silica pillar, 24 and Si nanoscrew 30 structure surfaces through radio frequency (RF) magnetron…”

Organic Light-Dependent Resistors with Near Infrared Light-Absorbing Conjugated Polymer Films

“…Light-dependent resistors (LDRs) or photoresistors (PRTs), which act as a light-sensing device due to the change of electrical resistance upon exposure to light, have been widely used for various applications such as smartphones, light control systems, camera shutter control, commercial light meters, etc. , The advantage of LDRs includes a simple device structure, which typically consists of the same kind of electrodes leading to no particular care paid to the polarity choice of electrodes. , To date, LDRs have been fabricated with inorganic materials such as cadmium sulfide (CdS), cadmium selenide (CdSe), lead sulfide (PbS), indium antimonide (InSb), perovskite, zinc oxide (ZnO), etc. − …”