Alternating-current and direct-current responses of light-emitting devices based on decacyclene Langmuir-Blodgett films

Light-emitting devices have been fabricated with Langmuir-Blodgett films of decacyclene. The devices have been operated under both direct-current (dc) and alternating-current (ac) modes. Frequency response of luminance of such devices under ac voltage has been studied, and moderately high-frequency electroluminescence has been observed from these devices. Light output characteristics, charge injection, and operation mechanism under the two modes have been compared and found to be different. Fowler-Nordheim tunneling mechanism has been found to be applicable in the de case, and space-charge-assisted Electron injection lowered the tunneling barrier ac modes. The transient characteristics of luminance have been studied which supported the role of space charges in device operation.