A Photodetector is a device that senses electromagnetic radiation, e.g., visible light, and generates instrument-readable electric signals. These devices have applications as sensors in aerospace/defense, oil and gas, utilities, construction, chemical industries, and the market for these devices was $292M in 2014 . Key performance metrics for photodetectors are their responsivity, or the change in output resulting from a change in input, and their spectrum, or the range of the radiation’s detectable frequencies. Photodetectors with high responsivity and broad range are attractive for imaging and sensing applications. Avalanche photodetectors can achieve this, but they are bulky and require high external bias voltage. Alternatively, phototransistors can achieve the desired responsiveness, but they require costly fabrication processes and/or low operation temperature, limiting applications. A photodetector design that achieves high responsiveness, a broad spectrum, and compact design has been developed that consists of multiple thin-film layers.
A Photodetector Consisting of Multiple Thin-Film Layers
The disclosed technology is a photodetector design that consists of multiple thin-film, heterostrcture layers. The design uses simple structures that can be fabricated using standard methods. Results based on a proof-of-concept device indicate that the proposed design achieves responsiveness improvements of three orders of magnitude versus the state-of-the-art graphene-based photodetector. Furthermore, by modifying the materials used within the design, the detectable frequency spectrum ranges from ultraviolet to infrared and terahertz frequencies. The device has applications to optical communication systems, safety and security, process control, environmental sensing, astronomy and defense.
- Optical communication systems
- Safety and security
- Process control
- Environmental sensing
- Easily fabricated design
- Highly responsive
- Wide spectral range of detection