Electroluminescence time dependence

H. Noguchi, T. Kondo, K. Murakoshi, and K. Uosaki, Visible electroluminescence from n-type porous silicon/electrolyte solution interfaces Time—dependent electroluminescence spectra, J. Electrochem. Soc. 146(11), 4166, 1999. 

Figure 160 Voltage (a) and current (b) dependence of the time-resolved EL in tetracene single crystals, (a) Reading from bottom to top are the bias voltage Uo, the rectangular voltage pulses (U— U0), the relaxation curves of electroluminescence (F) referring to the steady-stale EL level F0, the analyzing voltage pulses with varying duration time to and delay time t(. (b) The EL decay for two different thickness (d) tetracene crystals (crystal I d 16.5 pm pm crystal II d = 118 pm) under different steady-state current conditions (1 j 63 pA/cirr 2 j 23 pA/cm2 3 j = 0.7 pA/cm2 4 / 28 pA/cirr 5 6.1 pA/cm2). Adapted from Ref. [415],...

The photophysics of jt-conjugated polymers are reviewed in detail in other chapters of this book. (See, for example, Chapter 3.) Here, we focus on the electronic and photophysical phenomena that occur at the heterojunction between two different semiconductor polymers. The heteroj unctions are formed by combining four different polyfluorene copolymers in blend or bilayer thin films and are investigated using time-resolved and steady-state, temperature- and elec-tric-field-dependent photoluminescence measurements as well as electroluminescence and time-resolved spectroscopy. We review a body of work carried out in our laboratories over the last few years, and published in numerous journal articles (see refs. [13-17]). 

For the first time, the electroluminescent structures based on sol-gel derived SnOi and In203 films containing 30 wt.% EU2O3 and Tb203 are fabricated onto porous anodic alumina. The current-voltage characteristics and the dependence of emission intensity on annealing temperature are considered. 

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