Infrared Detector Materials and Technologies

Infrared detector research encompasses a wide array of semiconductor materials and device architectures designed to convert infrared photons into electrical signals with high sensitivity, low noise and fast response. Key material systems include mercury–cadmium–telluride alloys, III–V antimonide compounds such as InAsSb, type-II superlattices and emerging two-dimensional and colloidal quantum-dot materials. Device architectures range from photoconductors and photovoltaic diodes to barrier-based structures (nBn, pBn) and avalanche photodiodes, each engineered to suppress dark current and extend operating temperature. Complementary developments in quantum cascade detectors and monolithic integration on silicon platforms promise compact, mass-producible focal-plane arrays and on-chip spectroscopic systems. Advances in epitaxial growth, band-structure engineering and heterointegration have collectively driven enhancements in quantum efficiency, detectivity and high-temperature performance, enabling applications in thermal imaging, environmental monitoring, optical communications and spaceborne sensing.

Research from Nature Portfolio

Recent studies have introduced an advanced mid-wavelength infrared avalanche photodiode capable of high-temperature operation by incorporating a fully-depleted absorption and multiplication region. This design suppresses dark current density at temperatures up to 160 K while maintaining low excess noise, yielding noise-equivalent power on the order of 10⁻¹⁶ W Hz⁻¹ᐟ² and enabling imaging over long ranges without cryogenic cooling. Separately, a bias-selectable three-colour infrared photodiode based on InAs/GaSb/AlSb type-II superlattices has demonstrated sequential short-wave, mid-wave and long-wave detection through conduction-band offset and tailored doping. The three channels exhibit well-defined cut-off wavelengths and high quantum efficiency, all within a single two-terminal device, offering versatile multi-spectral imaging at elevated temperatures with simplified fabrication.

Infrared Detector Materials and Technologies publication trend

The graph below shows the total number of articles in infrared detector materials and technologies across all publications each year (not limited to Nature Index journals).

Technical terms

Avalanche photodiode (APD): A photodetector that uses impact ionisation to multiply charge carriers and achieve enhanced sensitivity.

Type-II superlattice: A periodic semiconductor heterostructure in which electrons and holes are confined in adjacent layers, enabling tailored band-gap energies.

nBn photodetector: A barrier-based diode in which an electron-blocking layer reduces dark current while allowing carrier collection.

Dark current density: The unwanted current flowing through a photodetector in the absence of light, which limits sensitivity.

Detectivity (D*): A figure of merit expressing a detector’s sensitivity, normalised to area and bandwidth, in units of Jones (cm Hz¹ᐟ² W⁻¹).

Quantum efficiency: The ratio of collected charge carriers to incident photons, indicating how effectively a detector converts light into current.

References

1. High-temperature mid-wavelength infrared avalanche photodiode with modified fully-depleted absorption and multiplication region. Communications Materials (2025).
2. High performance bias-selectable three-color Short-wave/Mid-wave/Long-wave Infrared Photodetectors based on Type-II InAs/GaSb/AlSb superlattices. Scientific Reports (2016).
3. Pushing the Room Temperature Continuous‐Wave Operation Limit of GaSb‐Based Interband Cascade Lasers beyond 6 µm. Laser & Photonics Review (2023).
4. Trends in Performance Limits of the HOT Infrared Photodetectors. Applied Sciences (2021).
5. Mid-Infrared InAs/InAsSb Superlattice nBn Photodetector Monolithically Integrated onto Silicon. ACS Photonics (2019).