Food quality examination device, food component examination device, foreign matter component examination device, taste examination device, and changed state examination device

摘要

A food quality examination device using a high-sensitivity light-receiving element. The light-receiving element includes a III-V compound semiconductor stacked structure including an absorption layer having a pn-junction therein, wherein the absorption layer has a multiquanturn well structure composed of group III-V compound semiconductors, the pn-junction is formed by selectively diffusing an impurity element into the absorption layer, a diffusion concentration distribution control layer composed of III-V group semiconductor is disposed in contact with the absorption layer on a side of the absorption layer opposite the side adjacent to the group III-V compound semiconductor substrate, the bandgap energy of the diffusion concentration distribution control layer is smaller than that of the group III-V semiconductor substrate, the concentration of the impurity element selectively diffused in the diffusion concentration distribution control layer is decreased to be 5×1016/cm3 or less toward the absorption layer.