搭建由半导体制冷片和光谱仪组成的LED变温发光特性测试系统,使用多通道温度测试仪记录芯片工作温度,得到LED芯片在30-80℃范围内的发光特性与温度的关系。结果表明:在输入电流恒定时,随着芯片材料温度的不断升高,LED的电功率和光功率降低,LED光效下降趋势明显;同时由于材料禁带宽度减小, GaN LED的蓝光峰值波长发生红移;通过上述测试,利用数值拟合方式得到了芯片发光特性与温度之间的函数关系。
A temperature changing LED spectral measurement system is built, which consisted of semiconductor refrigerating piece and spectrometers,using multi-channel temperature tester to test the chip′s temperature. The relationship between LED spectrum and temperature is measured from 30℃to 80℃. The tested result shows that when the input current is constant, with the temperature increasing, LED electrical power, luminous flux and electro-optic efficiency are reduced. GaN LED peak wavelength is red shift due to band gap diminishing. The function of temperature and light attenuation is obtained by numerical fitting test results.