Abstract
GaSb-related materials play an important role on fiber communication and monitoring. The atmospheric pollutants and human blood glucose sensing are just to match the absorption range of GaSb-related ternary and quaternary materials. The 1.3 and 1.55 μm wavelength are the main wavelength of signals being used in communication because of lower power loss and scattering. The absorption spectral range of atmospheric pollutants is 2.3-4.3 μm, and it is totally matched to the spectrum of GaSb-related materials. The traditional blood glucose monitoring method is stabbing into human skin and measuring glucose level. If we can detect the reflection spectrum of the light from a light source illuminated through human blood, we can have a non-invasion method to monitoring blood glucose. We use photolithography and Zn diffusion to form a p-n junction. Use plasma enhanced chemical vapor deposition (PECVD), E-gun evaporator, reactive ion etching (RIE) and wet etching to find the best diffusion and processing onditions. This developed technology will be used for the future work to fabricate photodetectors by using the GaSb-related ternary and quaternary materials in the near- and mid- infrared wavelength range. We analyze the characteristics of our devices by using electrical and optical measurements. I-V curves can get cut-in voltage, series resistance, breakdown voltage, and ideality factor. C-V curves can get built-in potential, bulk concentration and diffused carrier concentration. The dark current can be lower than 3 μA at the reverse bias of -0.2 V and breakdown is -3.34 V at room temperature can be measured by electrical measurement. The absorption spectral range is below 1.7 μm, and the responsivity is 0.71 A/W on 1.15 μm.