Design considerations for high-current photodetectors

• Published in: Journal of lightwave technology Vol. 17; no. 8; pp. 1443 - 1454
• Main Authors: Williams, K.J., Esman, R.D.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.08.1999; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Circuit properties; Density; Doping; Electric, optical and optoelectronic circuits; Electronics; Exact sciences and technology; Frequency; Fundamental areas of phenomenology (including applications); Geometry; High current; Illumination; Imaging detectors and sensors; Indium gallium arsenide; Indium gallium arsenides; Integrated optics. Optical fibers and wave guides; Lighting; Mathematical models; Optical and optoelectronic circuits; Optical elements, devices, and systems; Optics; Optimization; Optoelectronic devices; Photoconductivity; Photocurrent; Photodetectors; Physics; PIN photodiodes; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Semiconductor process modeling; Temperature; Semiconductor device; Thermal factor; Heating; High current; Theoretical study; Nonlinearity; Photodiode; p i n diode; Photodetector
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/50.779167

This paper outlines the design considerations for gigahertz-bandwidth, high-current p-i-n photodiodes utilizing InGaAs absorbers. The factors being investigated are photodetector intrinsic region length, intrinsic region doping density, temperature effects, illumination spot size, illumination wavelength, frequency, and illumination direction. Space-charge calculations are used to determine optimal device geometry and conditions which maximize saturation photocurrent. A thermal model is developed to study the effects of temperature on high-current photodetector performance. The thermal and space-charge model results are combined to emphasize the importance of thin intrinsic region lengths to obtain high current. Finally, a comparison between surface-illuminated p-i-n structures and waveguide structures is made to differentiate between the problems associated with achieving high current in each structure and to outline techniques to achieve maximum performance.