Diamond-like carbon based devices and methods of making and using the same which have improved electron emission and increased reliability. The device can include an anode with a layer of diamond-like carbon material such as amorphous diamond coated over at least a portion of the anode and a cathode. An intermediate member can be electrically coupled between the diamond-like carbon material and the cathode. Various additional layers and configurations can allow for improved performance such as multiple cathode layers and/or multiple intermediate layers. The presence of diamond-like carbon on the anode provides significantly improved electron emission with or without diamond-like carbon on the cathode. The devices can be configured as thermoelectric conversion devices such as an electrical generator or a cooling device, light emitting devices, or other electronic devices and can be conveniently formed.