Measuring the reflectance and the internal quantum efficiency of silicon and InGaAs/InP photodiodes in near infrared range. Ana Luz Muñoz Zurita 1) , Joaquin Campos Acosta 2) Alexandre S. Shcherbakov 1) , Alicia Pons Aglio 2) . 1) Department of Optics, National Institute for Astrophysics, Optics, and Electronics (INAOE), A.P. 51 y 216, Puebla, Pue., 72000, Mexico. Fax/Tel. 52 (222) 247 2940. E-mail: alex@inaoep.mx, azurita@inaoep.mx 2) Department of Metrology, Institute for Applied Physics (CSIC), Serrano 144, Madrid, 28006, Spain. Phone: 34 91 561 8806, ext. 326; Fax: 34 91 411 7651, ext. 206; E-mail: joaquin.campos@ifa.cetef.csic.es, alicia.pons@ifa.cetef.csic.es 1. Abstract. At the present time, silicon and InGaAs/InP photodetectors from different manufactures have rather low level of noise, a good uniformity of the surface response as well as a wide dynamic range and linearity. For these reasons they are exploited in the instruments for measuring optical radiation within the near infrared range 800-1600 nm. Furthermore, the silicon and InGaAs/InP photodetectors are used for maintaining the scales of spectral responsitivity in the above-listed spectral range in many laboratories. Due to the last application, we presented our studies of the reflectance and the internal quantum efficiency inherent in silicon and InGaAs/InP photodiodes from different manufactures. Both the reflectance and the internal quantum efficiency determine the photodiode spectral responsivity, which is the radiometric characteristic of interest in the fields where these devices can be used for optical radiation measurements. The responsivity will be known if both the reflectance and the internal quantum efficiency are known at every wavelength We have measured the reflectance of three silicon photodiodes and three InGaAs/InP photodiodes that were practically used to maintain scale of the spectral responsivity in the Institute for Applied Physics (CSIC). The results obtained show that we have an outstanding change between the reflectance of the photodiodes of the same set, which indicates that its necessary to measure the reflectance of every individual photodiode if an accurate reflectance knowledge is needed, its necessary to measure the reflectance of every individual photodiode to have a precise knowledge on the evolution of its reflectance. Key words: reflectance, near infrared range, photodiodes. 2. Introduction. The photodetectors are chosen as the first device of interest because of their simple structure, and since their analysis is a natural extension, almost an example, of our discussion of p-n diodes. Whereas the field of photodetectors goes way beyond that of semiconductor photodetectors, we restrict ourselves here to such devices. We will discuss P-i-N diodes, which are also referred to as photovoltaic detectors, photoconductors, solar cells and metal-semiconductor-metal photodetectors. The distinction between the different devices is somewhat artificial since many similarities exist between these devices but it enables to clearly separate the difference in structure, principle of operation and purpose of the devices.[2] Optical Components and Materials V, edited by Michel J. F. Digonnet, Shibin Jiang, John W. Glesener, J. Christopher Dries Proc. of SPIE Vol. 6890, 68900P, (2008) · 0277-786X/08/$18 · doi: 10.1117/12.763885 Proc. of SPIE Vol. 6890 68900P-1 2008 SPIE Digital Library -- Subscriber Archive Copy