We previously reported the spontaneous emission QE of one type of LED materials up to 800 K for the improvement of high temperature optocouplers 1. However, systematic understandings on optoelectronic materials and devices at high temperatures (above 500 K) are still very limited 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18. There are numerous groups studied optoelectronic materials and devices from cryogenic temperature to room temperature 2, 3, 4, 5, 6. Therefore, the development of high temperature optocouplers, which can be operated at elevated temperatures (over 500 K) with an extended lifetime, requires a systematic study of optoelectronic materials and devices at high temperatures. The optoelectronic materials, which can be utilized at high temperatures, are essential for the advance of high temperature optocouplers. The need for high-temperature optocouplers, which can be reliably operated over 500 K, is currently driven by the high-temperature requirements in the next generation high-density power electronics 1. The advance reported in this paper evidences the possibility of improving high temperature optocouplers with an operating temperature of 500 K and above. The spontaneous emission QE is approximately 30% for red for display LED material at 800 K. At 800 K, the spontaneous emission quantum efficiencies are around 40% for blue for lighting and blue for display LED materials, and it is about 44.5% for green for display LED materials. This model has been recently used extensively to calculate the internal quantum efficiency and its droop in the III-nitride LED. The spontaneous emission QE was obtained based on a known model so-called the ABC model. The spontaneous emission quantum efficiency (QE) of blue, green, and red LED materials with different wavelengths was calculated using photoluminescence (PL) spectroscopy. Commercial light emitting diode (LED) materials - blue (i.e., InGaN/GaN multiple quantum wells (MQWs) for display and lighting), green (i.e., InGaN/GaN MQWs for display), and red (i.e., Al 0.05Ga 0.45In 0.5P/Al 0.4Ga 0.1In 0.5P for display) are evaluated in range of temperature (77–800) K for future applications in high density power electronic modules.
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