A locker structure is disclosed. The separator assembly has a housing with an inlet port and an outlet port. A light emitting region sandwiched between a layer of first conductivity type and a layer of second conductivity type is disposed in the resonant cavity. A monomer containing an electron-withdrawing group and an electron-donative group represented by the following general formula : . The controller for moving the substrate transport apparatus moves the substrate transport apparatus, based at least partially upon input from the sensor, to position the end effector at a predetermined position relative to the substrate to pick up the substrate onto the end effector.