Photo-responsive Properties on Locally Confined Ultrathin Silicon Nanowires

Benjamin Thierry,Regina Stockmann,Andreas Offenhausser,Thomas Nann,Thomas Macdonald,Duy Tran,Bernhard Wolfrum

doi:10.3390/ecm-1-b001

Abstract

We present a concept of hybrid photo-responsive device based on the combination of ultrathin SiNW with quantum dots (QDs). High quality SiNW arrays have been fabricated using a novel top-down process. The SiNW arrays were able to detect light from the UV up to the visible range with good sensitivity, fast response and ultrahigh photo responsivity (R~ 104 A/W) at room temperature. The SiNW arrays have good stabilities over long term measurement as well as a range of experimental conditions (e.g. temperature 273 – 343 K) and even after strong UV radiation exposure (up to 585 J.cm-2). The SiNW arrays were coated with cadmium telluride (CdTe) QDs, and the hybrid QD sensitized devices displayed a significant improvement of the photocurrent measured under UV light while preserving their performance under visible light illumination. The sensitivity over a broad illumination range, the stability and high photoresponse of the new hydrid nanostructures is very promising towards the development of novel optoelectronic and photovoltaic devices.

Highlights

Silicon nanowires (SiNWs) are an exciting class of nanomaterials and their unique properties have been already demonstrated in a range of technological applications [1,2,3,4]
This is due to their remarkable physical properties, such as their high performance field-effect transistors (FET) [5, 6] and ultrahigh photo-responsivity [7]
The fast, stable and high photo response of the new hybrid nanostructures is very promising towards the development of novel optoelectronic and photovoltaic devices

Summary

Introduction

Silicon nanowires (SiNWs) are an exciting class of nanomaterials and their unique properties have been already demonstrated in a range of technological applications [1,2,3,4]. Contrary to conventional silicon photo detector, which has limited photo detection capabilities in the visible and near infrared light range, photo detectors based on SiNW structures are able to detect ultraviolet light with high responsivity [7, 18]. This unique property makes SiNWs promising building blocks for high performance photo-detectors and full-spectrum photovoltaic devices. The fast, stable and high photo response of the new hybrid nanostructures is very promising towards the development of novel optoelectronic and photovoltaic devices

Results and Discussion

Experimental Section

Conclusions