The research article was published by Shisheng Lin from Zhejiang University et.al.
Graphene exhibits exceptional optoelectronic properties for broadband photodetection, yet the responsivity and detectivity of graphene-based photodetectors is constrained. Integrating graphene with semiconductors as heterostructures enhances performance, but bandgap limitations of the semiconductor restrict previous demonstrations to narrow spectral ranges unsuitable for applications demanding sensitive color detection. GaAs is an ideal candidate to overcome these limitations, with its direct 1.42 eV bandgap and high mobility enabling high-performance photodetection from the visible to near-infrared. Furthermore, the ultrafast separation of photogenerated carriers across the graphene/GaAs interface offers the potential for substantial enhancements from localized surface plasmon resonances. This work realizes a plasmon-enhanced graphene/GaAs heterojunction photodetector with simultaneously ultrahigh responsivity, detectivity and broadband response across 325-980 nm, presenting exceptional sensitivity unrivaled by existing photodetectors.
The synergy between graphene and GaAs yields a remarkable broadband enhancement through the intricate overlap of the graphene/GaAs junction depletion region, surface plasmon near field, and GaAs absorption depth. This enhancement mechanism is particularly pertinent in graphene/direct bandgap semiconductor heterostructures like graphene/GaAs. The resultant heightened responsivity, detectivity, and wide spectral range position it as an exceptional photodetector, especially for applications necessitating sensitive color detection, such as CCD imaging.
As advancements in 5G and mobile technology propel the integration of advanced photoelectric sensors into daily life, the challenge lies in the shrinking photosensitive areas. However, this trend demands superior light sensing performance from these advanced photodetectors, amplifying the difficulty in accurately measuring quantum efficiency. Traditional methods struggle with focal shifts caused by wavelength dispersion, making it arduous to precisely capture the full-spectrum quantum efficiency curve within micrometer-level active areas.
In response, the Enlitech APD-QE, employing spatial light homogenizing technology and the ASTM “Irradiance Mode,” aptly measures quantum efficiency and key parameters for various advanced photodetectors like LiDAR sensors, TFT image sensors, InGaAs Photodiode and more. Traditional quantum efficiency systems face limitations in accurately measuring small-area photodetectors due to challenges in photon focusing and overcoming measurement errors caused by optical dispersion and aberration, impacting EQE spectrum curves. APD-QE overcomes these challenges and becomes a cutting-edge tool for cutting-edge light detectors!