Shao-Yu Chen at the Institute of Atomic and Molecular Sciences in Taiwan and associates have incorporated chlorophyll into graphene transistors to make light-activated switches, MIT Technology Review reports.

The new phototransistor design consists of two silver electrodes connected by a sheet of graphene. The graphene is then covered by a layer of chlorophyll using a method known as drop casting. .

This layer has a significant influence on the electronic characteristics of the device. When a voltage is set up between the silver electrodes, relatively little current flows.   However, when the chlorophyll is zapped by light of certain frequencies, the current increases dramatically. […]