Fabrication of CdS Nanorods on Si Pyramid Surface for Photosensitive Application

Abstract

It is the first time that cadmium sulfide (CdS) nanorods have been fabricated on silicon (Si) pyramid surface by the hydrothermal reaction method. In our work, the Si pyramid morphology is able to increase the adhesion between the CdS seed layer and Si wafer. Hence, it is critical for CdS nanorods to grow successfully. During the fabrication process, the glutathione is used as the complexing agent for the formation of the CdS nanorods. By continuously adjusting the experimental conditions, the thickness of the CdS seed layer, the concentration of the glutathione, and the temperature and time of the hydrothermal reaction, the optimal condition for CdS nanorods growth on Si pyramid surface is 80 nm seed layer, 0.2–0.3 mmol glutathione, 200 °C, and 1.5 h. The Cd and S elements have a ratio of 1:1.03 from the energy-dispersive spectroscopy test, which is in agreement with the stoichiometric composition of CdS. The CdS nanorods have a bandwidth of 2.22 eV through the optical absorption spectra. The photosensitivity response test results reveal these CdS nanorods on the Si pyramid structure have an obvious photosensitive effect. From the analysis, the CdS nanorods can grow on any morphological Si surface if the adhesion between the CdS seed layer and the Si surface is strong enough.

PbS/p‐Si NW Heterojunction Thin Film Device for Room Temperature NH3 Detection

“…[4][5][6][7][8][9] CdSÀ Si NW heterostructures are the most reported ones which can find potential use as nano LED, photodetectors and for photocatalytic hydrogen evolution. [10][11][12][13][14] Recently, our group demonstrated electricity generation from atmospheric moisture utilizing CdSÀ Si NW heterojunction thin films resulting in an output voltage of ~300 mV and an output current of ~300 μA. [15] Lead sulfide (PbS), a narrow band gap material (~0.4 eV) has emerged as an efficient absorbent layer for photovoltaic cells.…”

“…Different II–VI metal chalcogenides are reported in the literature to form heterojunction structures with Si NW which can be further exploited for advanced applications in various fields including energy generation and photodetectors [4–9] . CdS−Si NW heterostructures are the most reported ones which can find potential use as nano LED, photodetectors and for photocatalytic hydrogen evolution [10–14] . Recently, our group demonstrated electricity generation from atmospheric moisture utilizing CdS−Si NW heterojunction thin films resulting in an output voltage of ~300 mV and an output current of ~300 μA [15] …”

Electricity Generation from Atmospheric Moisture Using a CdS/p‐Si Nanowire Hetero‐Junction Device

“…Hayden et al were the first to report the fabrication of heterostructured nanowires with p‐type Si core and n‐type CdS shell using pulsed‐laser deposition (PLD) for the application as nano LEDs in 2005 [8,9] . Subsequently, there has been quite a few reports involving the application of CdS/Si heterojunction as photodetector [10–18] . A recent work by Lin et al reported the synthesis of CdS quantum dot (QD) decorated vertically aligned Si NWs arrays with enhanced activity and recyclable operability for photocatalytic hydrogen evolution [19] .…”

“…[8,9] Subsequently, there has been quite a few reports involving the application of CdS/Si heterojunction as photodetector. [10][11][12][13][14][15][16][17][18] A recent work by Lin et al reported the synthesis of CdS quantum dot (QD) decorated vertically aligned Si NWs arrays with enhanced activity and recyclable operability for photocatalytic hydrogen evolution. [19] The formation of p-n heterojunction at the interface of the Si NWs and the CdS QDs results in an internal electric field which facilitate the separation and transport of the photoinduced charge carriers thereby improving both the photoactivity and photostability of the Si NWs/CdS array composite.…”