Low-cost photodetector architectures fabricated at room-temperature using nano-engineered silicon wafer and sol-gel TiO2 - based heterostructures

Debika Banerjee; Ivy M Asuo; Alain Pignolet; Sylvain G Cloutier

doi:10.1038/s41598-019-54481-8

Low-cost photodetector architectures fabricated at room-temperature using nano-engineered silicon wafer and sol-gel TiO₂ - based heterostructures

Sci Rep. 2019 Nov 29;9(1):17994. doi: 10.1038/s41598-019-54481-8.

Authors

Debika Banerjee¹, Ivy M Asuo^{1

2}, Alain Pignolet², Sylvain G Cloutier³

Affiliations

¹ 1Dept. of Electrical Engineering, École de Technologie Supérieure, 1100 Notre-Dame Ouest, Montréal, QC, H3C 1K3, Canada.
² Institut National de la Recherche Scientifique (INRS), 1650 Boul. Lionel Boulet, Varennes (QC), J3X 1S2, Canada.
³ 1Dept. of Electrical Engineering, École de Technologie Supérieure, 1100 Notre-Dame Ouest, Montréal, QC, H3C 1K3, Canada. sylvaing.cloutier@etsmtl.ca.

Abstract

In the last decades, significant research has been done on the nanocrystalline forms of titanium dioxide (TiO₂). Amorphous TiO₂ has not been studied intensively despite being significantly less expensive compared to crystalline TiO₂. This study reveals significant improvement in UV-VIS photodetection properties from heterostructures fabricated in ambient environment using n-type silicon nanowire arrays and amorphous TiO₂ sol-gel. Our ultra-low-cost UV-VIS photodetectors can cover a wide range of applications. We report fast rise/decay time constants of 0.23 ms/0.17 ms and high responsivity up-to 6.0 A/W in the UV and 25.0 A/W in the visible range under low (1 V) external bias. The large surface area due to the nanowire array architecture leads to 2 orders of magnitude enhancement in photo-response. Besides the final electrode deposition, the entire device fabrication is performed using low-cost, all solution-based methods in ambient conditions. These low-cost UV-Visible broadband photodetectors can potentially serve a wide range of applications.