Flexible InGaAs/InAlAs avalanche photodiodes for short-wave infrared detection

Flexible detectors have gained growing research interest due to their promising applications in optical sensing and imaging systems with a broad field-of-view. However, most research have focused on conventional photodiodes of which the responsivity are limited at short-wave infrared due to the absence of internal multiplication gain. Here we have realized and demonstrated flexible thin-film InGaAs/InAlAs avalanche photodiodes on a mica substrate for short-wave infrared detection. This achievement was made possible by the development and implementation of a low-temperature bonding and well-optimized fabrication process. Our devices exhibit promising characteristics, including low dark current, good responsivity, and high multiplication gain. Even when subjected to bending conditions, the avalanche photodiodes maintain their general performance. The advent of such flexible InGaAs avalanche photodiodes with reliable and promising performance enables a significantly broader range of potential applications. The authors report flexibleInGaAs/InAlAs avalanche photodiodes, offering high responsivity, low dark current, and decentinternal gain in the SWIR range. Device performance remains stable under bending, supporting flexible sensing applications.