Primary research on accelerated degradation tests for IR-LEDs under high pulse currents

The IR-LED (Infrared Light Emitting Diode) is a kind of LED and can emit infrared ray under forward current excitation. It is widely used in communication and sensing area. Low power IR-LEDs usually work under low currents in continuous or pulse modes. However in real usage situation, users hope to improve IR-LEDs' transmit power and distance and the common practice is to use high pulse current to drive IR-LEDs. In this paper, an accelerated degradation test is conducted under high pulse currents which are set as work stresses for the IR-LED. The conditions of the test are keeping the peak value at 800 mA and pulse duration at the allowed maximum value 100 μs, and only changing the duty ratio. At last a primary lifetime prediction model about lifetime versus duty ratio is established, and the failure modes and mechanism of the IR-LED are discussed.