Patent ID: 7999231
Filing Date: 2011-08-16
Classification: B82Y,H01L,Y02E

Abstract:
1. A moisture detector configured to detect moisture in a test object, comprising: a light-receiving element including a Group III-V semiconductor laminated structure including an absorption layer having a pn-junction, or an array of the light-receiving elements, wherein the absorption layer has a multiquantum well structure composed of a Group III-V semiconductor, the pn-junction is formed by selectively diffusing an impurity element into the absorption layer, the concentration of the impurity in the absorption layer is 5×10 the moisture detector has a sensitivity to light having at least two wavelength ranges selected from a first wavelength range of 1.35 μm or more and less than 1.8 μm, a second wavelength range of 1.8 μm or more and less than 2.0 μm, and a third wavelength range of 2.5 μm or more and less than 3.0 μm, the light being reflected from the test object, and detects moisture using light in at least one wavelength range selected from the wavelength ranges in which the moisture detector has the sensitivity.