ZnS1-xTex混晶的压力光谱

研究了ZnS1-xTex(0.02≤x≤0.3)混晶的静压光致发光谱.每块样品都观察到一个峰值比相应混晶带隙低很多的发光峰,来源于束缚在Ten(n≥2)等电子陷阱上的激子复合发光,且随压力(0～7.0GPa)而蓝移.发光峰的压力系数比相应混晶带边的都要小,随着Te组分的增加而减小,与混晶带隙压力系数的差别也越来越大.由于压力下与发光峰对应的吸收能量逐渐接近并超过激发光的能量,与发光峰有关的吸收效率降低,发光峰积分强度随着压力增加而减小.据此估算了Ten等电子中心的Stokes位移.发现Stokes位移随着Te组分的增加而减小.     

InP（Yb）晶体结构和发光特性的研究

用离子注入法配合优化退火新技术制成了一种高效发光材料ＩｎＰ（Ｙｂ）；用高灵敏度激光光谱仪测量了该材料的发光特性（ＰＬ），并研究了离子注入和退火过程中发光特性的变化，对ＰＬ谱峰作出辨认；用Ｘ射线衍射谱（ＸＤＳ）测量分析晶格结构和注入损伤（缺陷）；研究了原材料的掺杂（Ｓｎ）对发光特性的影响；较深入地探讨了该材料的发光机制，并用一改进ＲＥ发光中心模型阐明该材料的激发发光过程。     

MBE高掺Be p-GaAs中E_g+△_0等高于带边的发光

我们在MBE高掺Be的GaAs中观察到了E_g+△_0和X_1~c-Γ_(15)~v之间之间跃迁的发光,讨论了高掺杂p-GaAs的E_g+△_0与本征GaAs的差别,在10-200K温度范围研究了E_g+△_0的温度依赖关系,并对X_1~c-Γ_(15)~v这一间接跃迁过程进行了讨论.     

MBE高掺杂n-GaAs:Si和p-GaAs:Be的光致发光谱

我们对MBE高掺杂的n-GaAs∶Si和p-GaAs∶Be进行了光致发光研究,详细比较了高掺杂n-GaAs和p-GaAs在光谱线型,峰值半宽,峰值位置等方面的差异,以及两者的发光与温度的关系.由分析得出,对于高掺杂的n-GaAs,填充在导带内较高能态(K≠0)的电子与价带顶(K=0)空穴的非竖直跃迁是主要的发光过程.而对于高掺杂的p-GaAs,则是以导带底附近(K(?)0)的电子和价带顶附近(K(?)0)的空穴竖直跃迁为主要发光过程.     

多孔硅的微结构和喇曼光谱

多孔硅（ＰｏｒｏｕｓＳｉｌｉｃｏｎ）是晶体硅于氢氟酸溶液中在硅衬底上形成的多孔态的硅材料。ＰＳ可见光区的强烈光辐射使其成为世界范围的研究焦点。本文用电化学方法制得了ＰＳ结构，扫描电子显微镜（ＳＥＭ）的结果表明ＰＳ是一个硅的毫微结构量子线的网络，光致发光（ＰＬ）谱表明ＰＳ发可见红光，而喇曼光谱显示一个在５１６ｃｍ（－１）附近的非对称峰，说明ＰＳ是一种新型的硅材料。     

Nanoseparation-inspired manipulation of the synthesis of CdS nanorods

CdS nanorods have been sorted by length using a density gradient ultracentrifuge rate separation method. The fractions containing longer rods showed relatively stronger oxygen-related surface trap emission, while the shorter ones had dominant band-edge emission. These results suggest that the final length distribution of CdS nanorods is not a result of random nucleation and growth, but is related to the local synthesis conditions. Inspired by these findings, different synthesis environments (N₂, air, and O₂) have been employed in order to tailor the length distribution. In addition to the rod length, the photoluminescence properties of CdS nanorods can also be manipulated. Increasing the oxygen partial pressure significantly changed the growth behavior of CdS nanorods by improving the anisotropic growth.      

Multicolor luminescent carbon nanoparticles: Synthesis, supramolecular assembly with porphyrin, intrinsic peroxidase-like catalytic activity and applications

Luminescent carbon nanoparticles (CNPs) are newcomers to the world of nanomaterials and have shown great impact in health and environmental applications as well as being promising building blocks for future nanodevices because of their fascinating photoluminescence and potential to serve as nontoxic replacements for traditional heavy-metals-based quantum dots. Herein, fluorescent CNPs have been prepared from candle soot by refluxing with HNO₃ and subsequently separated by a single centrifugation. The CNPs can be represented by the empirical formula C₁H_0.677O_0.586N_0.015Na_0.069, and have a size of 20–100 nm, height of 3.0 nm, lifetime of 7.31 ns ± 0.06 ns and quantum yield of ∼1.7%. Further studies demonstrate that: (1) the as-prepared CNPs exhibit excellent stability in biological media and their luminescence intensity does not change with ionic strength or pH in the physiological and pathological range of pH 4.5–8.8; (2) CNPs can act as electron donors and transporters and porphyrin can assemble onto CNPs through electrostatic and π-stacking interactions to form porphyrin-CNPs supramolecular composites; (3) CNPs have strong intrinsic peroxidase-like activity. Based on this intrinsic peroxidase activity, a simple, cheap, and highly selective and sensitive colorimetric and quantitative assay has been developed for the detection of glucose levels. This assay has been used to analyze real samples, such as diluted blood and fruit juice.      

立方相AlxGa1-xN/GaAs(100)的MOCVD外延生长

利用MOCVD生长技术在GaAs(100)衬底上生长了高质量的立方相AlGaN薄膜.通过光致发光 (PL)、扫描电镜(SEM)分析了不同NH3流量、不同生长温度对AlGaN外延层的结晶质量和表面形貌的影响.发现相对高的NH3流量和相对高的生长温度可以提高AlGaN外延层的结晶质量.     

氮化镓注镁(Mg:GaN)的光致发光

利用低压MOCVD在蓝宝石衬底上外延生长了GaN,用离子注入法掺入Mg杂质,退火后,进行光致发光测量,观察到显著的蓝光发射和黄带发射.光谱分析给出了与注入Mg离子相关的GaN禁带中能级的精细结构,其中: 间位Mg(Mgi)能级(导带下170meV)到替位Mg(MgGa)受主能级(价带上250meV)的跃迁产生了415nm发光峰; 该能级到价带上390meV能级的跃迁,以及带有紧邻N空位的替位Mg(MgGaVN)能级(导带下310meV)到 MgGa受主能级的跃迁,均产生了438nm发光峰.另外,退火使GaN晶格结构部分恢复,再现了黄带发射.