Effect of temperature on the intensity and carrier lifetime of an AlGaAs based red light emitting diode

Abstract

The influence of temperature on the intensity of light emitted by as well as the carrier life time of a standard AlGaAs based light emitting diode has been investigated in the temperature range from 345 to 136 K. The open-circuit voltage decay (OCVD) technique has been used for measured the carrier lifetime. Our experimental results reveal a 16% average increase in intensity and a 163.482-19.765 ns variation in carrier lifetime in the above temperature range. Further, theoretical and experimental analysis show that for negligible carrier density the intensity is inversely proportional to carrier lifetime for this sample.

Evaluation of tablet computers for visual function assessment

“…As has been shown in the literature, the luminance output decreased as the temperature increased (Dalapati, Manik, & Basu, 2013;Zhang, Li, Zhang, & Xi, 2008), except for the blue primary. Figure 5 shows the variations in luminance as a function of temperature, plotted as percentages of the luminance at 20°C, for white and the three primaries.…”

Influence of temperature on the performance of high power AlGaInP based red light emitting diode

“…For the temperature change from 293 to 243 K, the relative light intensity of the InGaN based blue LEDs increased by about 9 % whereas for AlGaInP based red power LEDs it increases about 10 %, on average (Weling et al 2011). In our previous work we also observed a similar trend of the variation of relative light intensity with temperature for AlGaAs based red LED, where a 16 % increase has been observed for a temperature change from 345 to 136 K (Dalapati et al 2013). Since the variation of n is sensitive to temperature (Chand and Kumar 1996), and is also not same for all LEDs, more number of LEDs should be characterized so that a theoretical basis of this variation can be addressed.…”

“…procured from RS Components, having a peak wavelength 624 nm. The LED was placed inside a bath type optical cryostat designed in our laboratory (Dalapati et al 2013;Manik et al 2000). With special care, liquid nitrogen was poured inside the liquid chamber of the cryostat which was pre-evacuated to a pressure 10 −4 Torr by using a high vacuum pumping unit (Model No.…”

“…In spite of the significant research efforts invested by many groups, these carrier transport mechanisms are still not well understood. Several publications highlight on the change of ideality factor, forward voltage, relative light intensity, carrier lifetime and reverse recovery time of LEDs with temperature (Weling et al 2011;Acharya and Vyavahare 1999;Dalapati et al 2013;Bergman et al 1995;Chen et al 2012;Hull et al 2008;Bolotnikov et al 2007). These literatures show that the variations of these factors with temperature for different types of LED are not same.…”

“…Several efforts have been made recently in order to develop both theoretically and experimentally the technique, which utilizes the open-circuit voltage decay (OCVD) process for determining the minority carrier lifetime (τ) of a LED (Dalapati et al 2013;Bergman et al 1995;Tapajna et al 2004;Bhattacharya et al 1985). Bergman et al (1995) reported that in GaAs/AlGaAs double heterostructures τ for acceptor concentration (N A ) 4 × 10 17 cm −3 varies from 150 to 20 nS for the temperature change 700-100 K. Also, the change of same for AlGaAs based red LED is 163.48-19.76 nS for the temperature change 345-136 K. This variation of τ clearly indicates that it is very sensitive to temperature and decreases with temperature and decrease of τ means that more recombination is taking place i.e.…”