Research On Infrared Photodetectors Based On Ⅲ-Ⅴ Compound Semiconductors

As a passive sensing technology,infrared photoelectric detection technology realized by using infrared light with long propagation distance,well anti-interference has important applications in aerospace remote sensing,atmospheric environment monitoring,medical monitoring,chemical detection and other fields.Infrared photodetectors have been extensively studied in just one hundred years since their birth.At the beginning of the 21^st century,the industry has put forward high requirements for infrared detectors,such as small size,light weight,low energy consumption,low price and high performance（SWa P³）,which further points out the direction of continuous innovation and breakthrough of infrared photoelectric detectors from material to device structure.Ⅲ-Ⅴcompound narrow-band gap semiconductor materials（Ga As,In P,Ga Sb,In As,In Sb and their multi-element alloys）have high carrier mobility,stable chemical properties,similar crystal lattice structure and adjustable band gap,the phodotdetectors fabricated withⅢ-Ⅴmaterial cover the range of Short Wave Infrared（SWIR）,Medium Wave Infrared（MWIR）and Long Wave Infrared（LWIR）with high detecting perfromance,and have been playing an important role in the research and application of infrared photodetectors.In order to suppress the high dark current,commercial mid-wave infrared photoelectric detectors often need to be equipped with low-temperature cooling dewar outside the detector,which seriously increases the size and manufacturing cost of the detector.The mid-wave infrared detector which can work at high temperature came into being and became an important research topic of infrared detectors.In this study,the phenomenon of light absorption enhancement and efficient carrier extraction in the low-dimensional structure of PN junction discovered by our research group was applied,and In As Sb/（Al,Ga）Sb interband transition quantum well infrared detector was prepared by usingⅢ-Ⅴantimonide,so as to realize a low-cost and small-volume high-temperature mid-wave infrared detector.In the research,the growth conditions for the transition of the interface of the Ga Sb-based Ga Sb buffer layer,large strain and high Sb component In As Sb and In As Sb/（Al,Ga）Sb interband transition quantum wells in Sb atmosphere were determined by molecular beam epitaxy technology,and a variety of photovoltaic In As Sb/（Al,Ga）Sb interband transition quantum well infrared detectors were successfully prepared.The photoelectric response spectrum verifies that the infrared detector with large strain In As Sb/Al Sb/Al Ga Sb interband transition quantum well can expand the detection wavelength from short-wave infrared to medium-wave infrared at 200 K,and it is determined from the energy band structure that the typeⅡdislocation interband transition quantum well infrared detector is a sufficient condition for realizing the detection of medium-infrared wave.This study provides an important theoretical and experimental basis for photovoltaic interband transition quantum well working at high temperature.In addition,in the aspect of visible-short wave infrared detection,compared with photoelectric infrared detectors of the same type with rigidity,flexible photoelectric devices and systems can achieve a wider range of applications,especially in new bio-integrated photoelectric systems and wearable consumer electronics.Compared with organic flexible electronics materials,photodetectors based on inorganicⅢ-Ⅴcompound semiconductors can achieve bending while maintaining inherent high performance,so they are an important choice for high-end flexible detectors.In this study,we demonstrated a broadband visible-SWIR flexible photodetector based on III-V compound semiconductor materials,which has a device size of 3×3 mm²,a working wavelength of 640 nm to 1700 nm,and a high detection rate of 5.18×10¹¹ cm hz^1/2/W@1550 nm,the response speed reaches MHz level.By adopting a simple top-down flexible device manufacturing process,we got rid of the high-cost and complicated process of flip-chip transfer of substrates for many times,and avoided the problems caused by using hydrofluoric acid.After 1,000 bending cycles with a radius of 15 mm,the prepared InGaAs PIN flexible extended short wave infrared detector still keeps its photoelectric performance stable.In addition,the mechanical failure modes of the flexible detector are also studied,which shows that the cracking and delamination failure modes are dominant in the upward bending and downward bending directions respectively.