MOISTURE DETECTION DEVICE, DETECTION DEVICE OF MOISTURE IN LIVING BODY, DETECTION DEVICE OF MOISTURE IN NATURAL PRODUCT, AND DETECTION DEVICE OF MOISTURE IN PRODUCT/MATERIAL

摘要

PROBLEM TO BE SOLVED: To provide a moisture detection device capable of detecting moisture with high sensitivity by using an InP system photodiode wherein a dark current is reduced without a cooling mechanism and light-receiving sensitivity is enlarged to a wavelength of 1.8 μm or more.;SOLUTION: This moisture detection device is described as follows: a light receiving layer 3 has a multiple quantum well structure of III-V group semiconductor; a pn junction 15 is formed by diffusing selectively an impurity element into the light receiving layer; band gap energy of a diffusion concentration distribution adjustment layer is smaller than band gap energy of III-V group semiconductor substrate; an impurity concentration in the light receiving layer is 5×10¹⁶/cm³ or less; an n-type impurity concentration before diffusion of the diffusion concentration distribution adjustment layer is 2×10¹⁵/cm³ or less, and has a low impurity concentration range in a thickness range on the light receiving layer side; and a detection device receives light having at least one wavelength included in an absorption band of water having the wavelength of 3 μm or less, to thereby detect moisture.;COPYRIGHT: (C)2011,JPO&INPIT