In Situ Ttemperature Measurements Via Ruby R Lines of Sapphire Substrate Based InGaN Light Emitting Diodes During Operation

The temperature of encapsulated green and ultraviolet light emitting diodes (LEDs) in operation has been measured optically via the ruby R lines emitted by the residual Cr3+ contaminations in the sapphire substrate. These two photoluminescent R lines, which are excited by the electroluminescence of the LED itself, show a well-characterized line shift as a function of temperature and pressure. The temperature is found to rise linearly with the applied forward current of the LED at a rate of ≈1 K/mA. This optical temperature measurement based on monitoring the two ruby R lines could qualify as a sensitive method for an in situ temperature sensor for other sapphire substrate based semiconductor devices such as laser diodes and field effect transistors.

Indium–gallium nitride (InxGa1-xN) single-quantum-well (SQW) light emitting diodes (LEDs), grown by metalorganic chemical vapor deposition on sapphire, were transferred onto Si substrates. The thin-film InxGa1-xN SQW LED structures were first bonded onto a n+-Si substrate using a transient-liquid-phase Pd–In wafer-bonding process followed by a laser lift-off technique to remove the sapphire growth substrate. Individual, 250×250 μm2, LEDs with a backside contact through the n+-Si substrate were then fabricated. The LEDs had a typical turn-on voltage of 2.5 V and a forward current of 100 mA at 5.4 V. The room-temperature emission peak for the InxGa1-xN SQW LEDs was centered at 455 nm with a full width at half maximum of 19 nm.


Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

• < Prev
• Next >