Theoretical investigation of BeZnO-based UV LEDs

Abstract

Two-dimensional numerical simulation is employed to assess a number of possible design approaches aimed at optimizing the internal quantum efficiency of BeZnO-based light-emitting diodes grown along the c-axis. First, we describe the material parameters and the numerical simulation methods used to study these devices. Second, the effects of thickness, doping, and alloy composition of the BeZnO electron blocking layer are analysed in order to maximise the carrier confinement in the active region. The optimum number of quantum wells and barrier doping level are also addressed, as well as the effects of the buffer layer thickness. Finally, the limitations on the device performance imposed by the nonuniform lateral current distribution are discussed.

Theoretical Study of the Performance and Efficiency Droop of a ZnO‐Based Multiquantum Well Light‐Emitting Diode

“…Several studies have proved that, because of the poor hole mobility, for a large number of QWs at a given injection current, the QWs farther away from the cap layer are rarely filled by holes and are passive in terms of optical generation. [5,21] Actually, the optimum number of QWs is associated with the capture and escapes rates and also the well width. Holes, with poor mobility, are able to attain the wells nearer to the p-contact, but electrons with much higher mobility than the holes can penetrate to more distant wells.…”

ZnO-based deep-ultraviolet light-emitting devices

“…[62] In order to improve the device performance of BeZnObased UV LED further, two-dimensional numerical simulation was employed to assess a number of possible design approaches aiming at optimizing the internal quantum efficiency (IQE) of BeZnO-based LED grown along the c axis. [63] For a high-efficiency operation at a wavelength of 360 nm, the effects of thickness, doping, and alloy composition of BeZnO electron blocking layer (EBL) in this heterostructure were in detail analyzed to maximize the carrier confinement in the action region. They found that if the EBL is thicker than 10 nm and has a Be molar fraction in excess of 11%; it can operate effectively as long as the doping is of p-type and at least equal to 5×10 18 cm −3 in concentration.…”