부산대학교 도서관

Uncooled bridge photodetectors based on InAs/InAsSbP heterostructures for the mid-IR region of the spectrum are presented. The bridge structure is distinguished by the fact that the contact pad is placed outside the photosensitive mesa and is connected to it only by an air bridge contact. This design makes it possible to reduce the area of the p–n junction and the capacitance of the device, which leads to an increase in speed without loss of detectivity. The InAs/InAsSbP heterostructures were grown by vapor-phase epitaxy on InAs substrates with (111) orientation. The developed photodetectors have maximum spectral sensitivity in the range of 2.8–3.1 μm and differential resistance at zero shift R0 = 1.0–5.6 kΩ. The capacitance of the best devices is C = 3.4–3.6 pF at Urev = 0 V. The speed of the photodetectors was studied with an InGaAsP/InP laser with emission wavelength of 1.55 μm. The response time determined from the leading edge of the photoresponse is 200 ps. The created bridge photodetectors can be used to detect laser pulses in the range of 1.1–3.8 μm. [ABSTRACT FROM AUTHOR]