Figure 2
From: Non-synchronization of lattice and carrier temperatures in light-emitting diodes
Junction-temperature measurements of FVM, CRS, TC and TI.
(a) Take blue InGaN/GaN LED (B1#) as the example. In reference to the linear relationship between 
and 
, we deduce the value of 
to be 
°C. (b) Relationship between 
and Raman redshift for the B1# sample when the LED chip is lit at small currents (
). The peak at 
°C has shifted to the left slightly. (c) Relationship between 
and Raman redshift for B1# sample when the LED chip is lit at large currents. At steady state and 
, for example, we measure Raman shift to obtain the peak location. Next, utilizing the 
and Raman shift relationship in b, we obtain 
°C. (d) Correlation between peak location and 
. (e) Junction temperature versus the current for B1# sample. In the absence of PISO, results obtained by CRS, TC and TI agree closely with one another, but differ appreciably from those obtained by FVM. Due to the disturbance of large noises, 
cannot be reliably measured in CRS for B1# sample at 
. (f) Junction temperature versus the current for G1# sample. (g) Junction temperature versus the current for R1# sample.
