Electroluminescence intensity

New results on the influence of uniaxial stress up to / = 4 kbar along [110] and [1-10] directions on the electroluminescence spectra of laser diode nanostructures p-ALGai-xAs/GaAsi.yP,/ -AlxGai.xAs are presented. With the increasing stress, the emission spectra demonstrate a blue shift of up to 20-25 meV at P = 3-4 kbar, while the electroluminescence intensity and light efficiency increase under compression. The results are discussed in terms of changes in the band structure under an uniaxial compression. 

Figure 2. Electroluminescence intensity as a function of time for a metal/EB/PPV.PPyV/EB/ITO device driven by a 1 Hz sinusoidal voltage metal...

Figure 4. Electroluminescence intensity and current density vs. time for an MI2 doped MEH-PPy)/rrO device at TV in the forward bias mode. Reproduced with permission from Synthetic Metals (in press). Copyright 1998 Elsevier Science Ltd.

Figure 5. Normalized electroluminescence intensities of light emission (at 580nm) vs. time fox Alll2-doped MEH-PPV/ITO device operated at 12V and 16V in the forward bias mode respectively. Reproduced widi permission from reference 12. Copyright 1997 Society of Photo-Optical Instrumentation Engineers.

FIG. 4 Electroluminescence intensity for PP films vs. the UV aging time short irradiation time (O) and long irradiation time ( ). (From Ref. 35.)... 

The tum-on current shifts to lower electric fields with increasing n - according to the facilitated injection and transport of holes (oxidation demonstrated by the arrows in Fig. 11.9(a)). Figure 11.9(c) shows the relative intensities of the electroluminescence as a function of the current density. The highest value ij = 10 was measured for 2c (n = 3). The relative electroluminescence intensities (Fig. 11.9(c)) at a current density of 1 mA cm show a dependence on n which... 

Y.I. Golovin, R.B. Morgunov, A.A. Baskakov, S.Z. Shmurak, Effect of a magnetic field on the electroluminescence intensity of single-crystal ZnS. Phys. Solid State 41 (1999) 1783-1785. 

One can see that the electroluminescence intensity gradually inaeases and reaches saturation level, but the signal onset is delayed by td with respect to the step-like applied voltage. The delay time tq corresponds to the time required to accumulate space charges at the p/n junction region of OLED thus, it is... 

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