Single-transistor spectrometer via Burstein–Moss absorption edge modulation in compound semiconductors

Abstract

As on-chip photonic systems evolve toward miniaturization and integration, achieving high-performance spectral analysis within a minimalist architecture remains a critical challenge, typically constrained by the trade-off between spatial resolution and spectral channels. Here, we propose a universal design strategy for a single-transistor computational spectrometer based on the gate-controlled Burstein–Moss effect, which enables the dynamic electrical modulation of the optical absorption cutoff, thereby allowing the incident spectrum to be reconstructed solely from a single current–voltage (I–V) curve. Through self-consistent simulations, systematic selection criteria for the active layer are established, prioritizing a small electron effective mass (me*) and a high band edge extinction coefficient (κ). Simultaneously, the gate dielectric design is optimized based on the trade-off between electrostatic control capability and tunneling leakage suppression. As a proof-of-concept, a miniaturized single-transistor spectrometer model integrating a GaAs-on-insulator active layer with HfO2 is numerically demonstrated. Coupled with an adaptive regularization algorithm, the spectrometer exhibits exceptional spectral reconstruction capabilities, achieving a narrowband spectral resolution of ∼4.2 nm and an ultra-high wavelength positioning accuracy of ∼0.04 nm, along with the high-fidelity recovery of dense doublets (∼6 nm separation) and broadband continuous spectra. Furthermore, it demonstrates powerful spatial-spectral decoupling capabilities in array-level imaging and exceptional algorithmic resilience against physical degradation. This work provides a versatile device design blueprint for developing low-cost, high-performance, and process-compatible on-chip integrated spectral analysis systems.