Related Experiment Video
Updated: Dec 17, 2025

Production and Characterization of Vacuum Deposited Organic Light Emitting Diodes
Published on: November 16, 2018
Optical Capacitance/Conductance-Voltage Characteristics of Stored Charges in Organic Light-Emitting Diodes
Chengwen Zhang1,2, Zheng Xu2, Peng Wang2
1Department of Physics, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
Abstract:
In this paper, capacitance/conductance-voltage characteristics (C/G-V) under illumination was achieved to investigate the dynamic mechanism of stored charges in OLEDs with a structure of ITO/ PEDOT:PSS/PMMA/Alq3/Al. For all devices, at least two peaks presented in the optical capacitance-voltage curve. Compared to curves of devices under dark, the first peak increased remarkably with a deviation to V, which can be explained in the form of stored charges combined with the optical conductance characteristics. It was also found that a great decrease in capacitance is followed by the collapse of the first peak with PMMA thickness increased. It can account for the presence of interfacial charges, which is proved further by the conductance curves. To the device with 10 nm PMMA, a third peak took place in optical capacitance and it was due to the storage of electrons by PMMA. Also, the first capacitance peak enhanced approximate linearly as the illumination power increased, which can verify the contribution of the stored charges. Additionally, it shows the potential for the stored charges in optical detections.
Related Concept Videos
Capacitors and Capacitance
When the conductors are two identical parallel plates, it is called a parallel plate capacitor. When battery terminals are...
Dielectric Polarization in a Capacitor
MOS Capacitor
The metal gate is typically made from highly conductive materials such as aluminum or polysilicon. Beneath the metal gate lies a thin layer of...
Energy Stored in Capacitors
By integrating the equation that relates voltage and current in a capacitor, one can derive an equation for the voltage across the capacitor at any given time. This equation is crucial in understanding and predicting the behavior of capacitors in...
Susceptibility, Permittivity and Dielectric Constant
Energy Stored in a Capacitor

