Analysis And Research On The Aging Mechanisms Of GaN-based LED

Semiconductor light-emitting diodes were widely used in automotive, traffic lights, landscape lighting, mobile phones and other fields. The power LEDs as a key component of semiconductor lighting, which beared the range of the static electricity, humidity, large current temperature and other factors all affected the lifetime of the LEDs.In order to study the mechanism of LED aging, which research work were based on the static electricity, temperature, high current and other factors’ research work as follows:(1) Explained the significance of study the aging mechanisms of LEDs and emitting principle of LED. Introduced the reliability of characterized amount, reliability test, accelerated life test and the derivation of the model.(2) Studied the power GaN-based blue and white LEDs antistatic ability. Provided different intensity static electricity combating different LED chips. Comparatived and analyzed the trends of LEDs’luminous Flux and I-V curve were combated before and after. For further research the of static electrostatic effects on LEDs failure mechanisms. The aging test at normal temperature, provided a forward current of900mA, continuous aging700h. According the luminous flux of LEDs found that which were combated by reverse static electricity decay rapidly and quite serious, instead of the shock by the positive static electricity LEDs affected were smaller.(3) Research the influence of temperature on LEDs the optical and electrical parameters. Variable temperature experiments in the range of5～75℃, the forward current is set to350mA. Studied the correlated color temperature, luminous flux, the radiant flux, the peak wavelength, the luminous efficiency, voltage and other parameters of LED were affected by temperature. (4) Introduced the method of LED aging test and set temperatures. Temperature accelerated aging test temperature were85℃and25℃, the forward current is set to700mA and continuous aging800h. Measured and recorded the luminous flux, Luminous efficiency and other optical parameters on a regular basis. The current accelerated aging tests were at the normal temperature. Two kinds of LEDs were set900mA and700mA operating current. According the experiment data deduced the average working life of LED that worked at specific conditions.AS the limited experimental conditions, the temperature reliability of experiment is set to5～75℃, the resulting data support the use of a smaller scope, requires further study.