Issue No. 3, December

Abstract

Novel tunable p-type thin film transistors (TFTs) were developed by adopting Cu₂O/SnO bilayer channel scheme. Using Cu₂O film produced at a relative oxygen partial pressure O_pp of 10% - as an upper layer - and 3% O_pp SnO films - as lower layers - we built a matrix of bottom gate Cu₂O/SnO bilayer TFTs with different thicknesses. We found that the thickness of the Cu₂O layer plays a major role in the oxidization process exerted onto the SnO layer underneath. The thicker the Cu₂O layer the more the underlying SnO layer is oxidized, and hence, the more the transistor mobility is enhanced at a certain temperature. Both the device performance and the required annealing temperature could then be tuned by controlling the thickness of each layer of the Cu₂O/SnO bilayer TFT.

Abstract

In this communication, the use of gallium nitride doped with beryllium as an efficient converter for white light emitting diode is proposed. Until now beryllium in this material was mostly studied as a potential p-type dopant. Unfortunately, the realization of p-type conductivity in such a way seems impossible. However, due to a very intensive yellow emission, bulk crystals doped with beryllium can be used as light converters. In this communication, it is demonstrated that realisation of such diode is possible and realisation of a colour rendering index is close to that necessary for white light emission.

Abstract

GaN-based InGaN/GaN self-organized quantum dots and InGaN quantum dots (disks) in GaN nanowires are important nanostructures with potential advantages over planar quantum wells, including luminescence at the longer visible wavelengths. We describe the epitaxy and characteristics of red-emitting InGaN/GaN quantum dot edge-emitting lasers and InGaN/GaN nanowire light emitting diodes, which can be used in a host of applications.