Gas monitoring equipment, combustion state monitoring device, aging monitoring equipment, and the impurity concentration monitoring device

摘要

PPROBLEM TO BE SOLVED: To provide a gas monitoring device or the like that can reduce a dark current without a cooling mechanism and can monitor a gas with high sensitivity by using an InP type photodiode with a light receiving sensitivity expanded to a wavelength of ≥1.8 μm. PSOLUTION: A gas monitoring device includes a light receiving layer 3 having a multiquantum well structure of a group III-V semiconductor and each pn junction 15 is formed by selective impurity element diffusion in the light receiving layer, the concentration of the impurity in the light receiving layer is ≤5×10SP16/SP/cmSP3/SP, and the gas monitoring device receives light having at least one wavelength of ≤3 μm to detect a gas component and the like contained in the gas. PCOPYRIGHT: (C)2011,JPO&INPIT