Long‐term Reliability Prediction of 935 nm LEDs Using Failure Laws and Low Acceleration Factor Ageing Tests

Abstract

Numerous papers have already reported various results on electrical and optical performances of GaAs-based materials for optoelectronic applications. Other papers have proposed some methodologies for a classical estimation of reliability of GaAs compounds using life testing methods on a few thousand samples over 10 000 hours of testing. In contrast, fewer papers have studied the complete relation between degradation laws in relation to failure mechanisms and the estimation of lifetime distribution using accelerated ageing tests considering a short test duration, low acceleration factor and analytical extrapolation. In this paper, we report the results for commercial InGaAs/GaAs 935 nm packaged light emitting diodes (LEDs) using electrical and optical measurements versus ageing time. Cumulative failure distributions are calculated using degradation laws and process distribution data of optical power. A complete methodology is described proposing an accurate reliability model from experimental determination of the failure mechanisms (defect diffusion) for this technology. Electrical and optical characterizations are used with temperature dependence, short-duration accelerated tests (less than 1500 h) with an increase in bias current (up to 50%), a small number of samples (less than 20) and weak acceleration factors (up to 240).

Performance Characterization and Theoretical Modeling of Emitted Optical Power for High-Power White-LED Devices

“…In particular, optical power variation mechanism of InGaN/GaN LEDs should be characterized by two different working zones limited by the threshold current (I th ) [13]. When current is lower than a threshold value, typically <10 mA, optical power will exhibit a quadratic increase with current.…”

“…Nowadays, few mathematical models of optical power are presented for LED devices, especially the model of optical power relation with junction temperature and injection current. An experimental method was conducted to characterize optical power for commercial InGaAs/GaAs LEDs [13]. In this paper, optical current curve is measured by two different current working zones.…”

Reliability investigations of 850 nm silicon photodiodes under proton irradiation for space applications

“…Current-voltage characteristics can particularly provide suitable information about transport of electrical carriers inside the active zone [6]. A semiconductor analyser (Keithley 236) was used to observe gradual changes in current-voltage before and after irradiations.…”

Failure Mechanisms in Packaged Light-Emitting Diodes Under Gamma Radiations: Piezoelectric Model Based on Stark Effect

“…Numerous papers have reported that temperature and/or high current injection lead to more than two different failure mechanisms in optoelectronic devices [1], significantly reducing device performance parameters such as efficiency, output power, and lifetime; degradation laws used in this case are then exclusively empirical. The actual integration of optoelectronic devices in space mission is difficult because of the sensitivity of these devices regarding radiations.…”