Item Details

title

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

author

Xu, Junwei

abstract

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.

subject

charge carriers

exciton kinetics

light emitting devices

pervoskite materials

semiconductor thin films

contributor

Carroll, David L. (committee chair)

Williams, Richard T. (committee member)

Üçer, K. Burak (committee member)

Geyer, Scott M. (committee member)

Gulthold, Martin (committee member)

date

2018-05-24T08:36:00Z (accessioned)

2019-05-23T08:30:12Z (available)

2018 (issued)

degree

Physics (discipline)

embargo

2019-05-23 (terms)

identifier

http://hdl.handle.net/10339/90701 (uri)

language

en (iso)

publisher

Wake Forest University

type

Dissertation