Abstract: A device includes: a mesa stripe structure comprising a semiconductor in a stripe shape extending in a first direction, with first and second portions spaced apart in the first direction, and a third portion between the first and second portions; and an electrode pattern including a first electrode overlapping with the first portion but not overlapping with the second portion, and a second electrode overlapping with the second portion but not overlapping with the first portion. The first and second electrodes are separated. The electrode pattern comprises a metal in a shape of not overlapping with the third portion. The electrode pattern includes an adjacent area not overlapping with the mesa stripe structure. The adjacent area is next to the third portion in a second direction orthogonal to the first direction, and is on a semiconductor layer continuous to the mesa stripe structure.

Abstract: An electronic receipt system includes a terminal device, a first memory unit which a first user has, and a second memory unit which a second user who is a trading partner of the first user has. The terminal device includes biometric authentication obtaining means to obtain biometric authentication information of the first user and biometric authentication information of the second user; electronic tally generating means to generate electronic tallies based on the biometric authentication information of the both users; electronic receipt generating means to generate electronic receipts including transaction information of the first user and the second user, the electronic receipts including a first electronic receipt having one of the electronic tallies and a second electronic receipt having another of the relevant electronic tallies; means to store the first electronic receipt in the first memory unit; and means to make the second electronic receipt to be stored in the second memory unit.