Charges and Excitons in Organic and Pervoskite Light Emitting Materials and Devices

Charge balance in organic light emitting structures is essential to simultaneously achieving high brightness and high efficiency. In DC-driven OLEDs, this is relatively straight forward. However, in the newly emerging, capacitive, field-activated AC-driven organic devices, charge balance can be a challenge. We introduced the concept of gating the compensation charge in AC-driven organic devices and demonstrated that this can result in exceptional increases in device performance. To do this we replaced the insulator layer in a typical field-activated organic light emitting device with a nanostructured, wide band gap semiconductor layer. This layer acts as a gate between the emitter layer and the voltage contact. Time resolved device characterization shows that, at high-frequencies (over 40,000Hz), the semiconductor layer allows for charge accumulation in the forward bias, light generating part of the AC cycle and charge compensation in the negative, quiescent part of the AC cycle.

Grantor dc:publisher

Wake Forest University

Year dc:date.issued

2018

Author dc:creator

• Xu, Junwei

• charge carriers

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10339/90701

OAI identifier oai:identifier

oai:wakespace.lib.wfu.edu:10339/90701