Highly Efficient Filterless Bilateral Majority Carrier‐Type Color Photodetectors

Abstract Photodetectors (PDs) are essential for promoting the modern technology‐reliant lifestyles. Accordingly, the demand for efficient PDs with built‐in signal amplification capabilities is constantly increasing. Generally, built‐in signal amplification is achieved using an avalanching process that operates at a high bias voltage with inevitable excess noise. In this study, back‐to‐back Schottky diodes (BTB SDs) are designed to demonstrate a significant amplification of signals at low bias voltages with relatively low excess noise. Furthermore, the detection efficiency is bilateral and relies less on the illuminated junction or the bias polarity, but is influenced by the wavelength of the illuminating light owing to the specific device structures employed. This enables the identification of the color of the incident light without using any color filters. The BTB graphene–insulator–silicon‐on‐insulator (BTB G–I–SOI) PDs fabricated with controlled interfacial oxides exhibit photoresponsivity up to 2.01 × 10⁴ A W⁻¹, specific detectivity of 1.57 × 10¹⁴ cm Hz^1/2 W⁻¹ at 5 V, and a rapid response (≈0.3 ms) for a two‐millimeter‐long channel. Thus, BTB G–I–SOI PDs are highly efficient filterless color sensors that establish a novel route for diverse applications of PDs.