In order to analyze the optoelectrical characteristics of organic electrolu
minescent (OEL) devices, a response time measuring system was established.
This system contains a brightness detector with a fast response photoamplif
er tube (PMT), a power supply, and a PC computer with an ultra-fast data co
llection card. The fast response data collection card installed in the PC c
omputer controls the entire course of measurements. The power supply applie
s a constant voltage to the brightness detector and a pulse voltage to the
OEL device to enable it to emit light. The brightness detector receives the
light emitted from the OEL device. Both the brightness and driving voltage
signals are transferred directly to the computer. Then the voltage-time an
d brightness-time curves are simultaneously recorded and, finally, the devi
ce response time is easily obtained from these curves. The lowest response
time of this system that can be measured is 50 ns. With this system, the re
sponse times of the OEL devices driven by different voltages have been meas
ured.