GaN基光电子材料的制备与性能研究-物理学 凝聚态物理专业业论文.docx

能，发现a-GaN薄膜套良好的场发射性能，低的开启场秘较大盼发射电流，F-N 能，发现a-GaN薄膜套良好的场发射性能，低的开启场秘较大盼发射电流，F-N 曲线的非线性来源于低场下的热电予发射和高场下的隧穿发射。 3．利用氨还原法在不同还原温度下制备了GaN以及GaN：RE纳米颗粒。利 震XRD与TEM分褥了纳米颗粒能结构，对比分析发现稀±掺杂以后，晶粒尺 寸大幅度减小；Raman谱出现了两个被c刍空间群所限制的一阶Raman散射：251 与415 cm一，前者源于表面缺陷和尺寸限制效应，后者源于八面体Ga-N6结构的 振动；光致发光结果表明剩用简单氨还原法获褥了高结晶质量的GaN纳米颗粒， 利用EDS与XPS分析了其化学成分，结果表明所有的目标元素都出现了，N原 子百分比略大于Ga的原子百分比且N不完全成键，这些结果从侧面证实了Ga-N6 的存在；室温光致发光测量结果显示GaN：RE都具有很静静发光性能，这些为其 在电致发光工业领域的应用提供了科学依据，且稀士特征峰的强度随着还原温度 的升高丽增强，随着稀土浓度的增大，强度先增强后减弱，并分析了其原因；最 蜃，测量了发光的激发谱，结果显豕GaN：RE的吸收主要是GaN基质麴吸收。 关键词：GaN；光学性质；电学性质；稀土掺杂 Il 兰州大学博士学位论文Abstract 兰州大学博士学位论文 Abstract Gallium nitride(Gab／)has been considered to be the most promising optoclectronic material for many applications．GaN·based optoelectronic materials have been attracted much attention in the last decade．Preparation and characterization of GaN-based optoelectronic materials arc becoming one of the most important focuses in the fields of physics and material． In this thesis，preparation and properties of GaN were studied and results are listed as follows： (1)The GaN films were prepared under different Ar pressures by DC spuRering method．The films were characterized by structural，optical and electronic analysis methods．The results show that the structure of the films Was amorphous．The transmission ratio and optical gap are largest when no Ar was present in the sputtering gas and the other optical properties were studied．Also，the GaN：RE films Were prepared by the DC sputtering method at room temperature,too．PL results show that the films exhibit intra-4ftransitions ofRE3+at room temperature． (2)The I-V curves of MIS structure of a-GaN film Were measured at different temperatures．The results show that the mechanism of DC conductance is SCLC effect． The I．V curves show that the a-GaN film exhibits semiconductor conductance character and the active energy Was calculated from curves．The information of a-GaN film defects Was characterized by Q-DLTS method and the results were consistent with the re