Development of Light Emitting Devices in Wide Band Gap MetalOxide/Nitride Systems using Pulsed Laser Deposition and Focused Ion Beam Technology

9813819 Iliadis PIS建议研究发光过程，并开发基于ZnO/GaN系统的新型发光器件。我们的初步研究表明，用脉冲激光沉积(PLD)方法在蓝宝石衬底GaN上外延生长的氧化锌薄膜具有较高的结晶度和光学质量。薄膜的质量使得产生的激子发光强度比质量最好的GaN层高四到五倍[1]。此外，有报道指出，在室温(RT)下，氧化锌具有比GaN(100 cm-‘)更高的光增益(300 cm-’)和更高的激子结合能(60 meV比GaN的28 meV)[3]，因此它有很大的潜力成为比GaN更有效的室温紫外蓝光发射体。我们的建议旨在了解和提高这种材料体系的光学性能，并开发出发光器件的原型。我们的工作将包括：(A)多层结构的PLD生长，为提高薄膜和界面质量而进行的生长过程的研究、建模和模拟，(B)针对生长的薄膜的结构(缺陷/应变)、电子(杂质掺入/场效应)和光学性质的光发射过程(辐射/非辐射复合、自发/受激发射)的研究，以及(C)利用光刻技术和聚焦离子束(FIB)技术设计和制造尺寸从微米到纳米尺度的紫外蓝光发射器件和测试结构的原型。

9813819IliadisThe PIs propose to study the light emission processes and develop novel light emitting devices based on the ZnO/GaN system. Our preliminary studies indicate that ZnO films grown epitaxially on GaN on Sapphire by pulsed laser deposition (PLD), are of high crystalline and optical quality. The quality of the films is such that the excitonic luminescence intensity produced is four to five times higher than that seen in the best quality GaN layers [1]. Furthermore, reports indicate [2] that ZnO has higher optical gain (300 cm-') than GaN (100 cm-') at room temperature (RT), and higher exciton binding energy (60 meV versus 28 meV for GaN)[3], thus suggesting a strong potential for ZnO to become a more efficient room temperature UV-blue light emitter than GaN. Our proposal seeks to understand and improve the optical capabilities of this material system, and develop prototype light emitting devices. Our work will include:(a) the PLD growth of multilayered structures, the study, modeling, and simulation of the growth processes for improved film and interface quality, (b) the investigation of the light emission processes (radiative/non-radiative recombination, spontaneous/stimulated emission) with respect to the structural (defects/strain), electronic (impurity incorporation/field effects), and optical properties of the grown films, and (c) the design and fabrication of prototype UV-blue light emitting devices and test structures, ranging in sizes from microns down to nanoscale dimensions using both photolithographic techniques and focused ion beam (FIB) technology.***