水热法制备ZnS∶Cu纳米晶及其光致发光性能

Photoluminescence of ZnS∶ Cu nanocrystals by hydrothermal method

采用水热法制备了不同掺杂浓度的ZnS∶Cu（0-0.6%（原子分数））纳米晶.结果表明,ZnS∶Cu纳米晶为立方晶系闪锌矿结构,晶粒尺寸在3-4nm之间;相比未掺杂的ZnS纳米晶,掺杂ZnS∶Cu纳米晶在500nm 处产生了发射光谱（PL）.这是由于发光中心位于446和468nm 两个PL光谱与ZnS自身的缺陷有关,发光中心位于500nm 的绿光为浅施主能级（S缺陷）与铜t2能级之间跃迁而产生.并且其发光强度随掺杂浓度显著增强,当浓度为0.4%（原子分数）时达到最大值,进而发生了浓度淬灭现象.

In this paper,Zn S∶ Cu( 0-0. 6at%) nanocrystals( NCs) were synthesized by hydrothermal method. The results show that the as-prepared NCs are confirmed to be the cubic zinc blende structure and their average size are about3-4 nm. Compared with the non-doped Zn S NCs,the Cu-doping Zn S NCs has an additional photoluminescence spectrum at the wavelength of about 500 nm. Two peaks centered at 447 and 468 nm are related with native defects( sulfur vacancy) of Zn S. Moreover,the PL spectra of Cu-doping Zn S NCs centered at 500 nm should be due to the recombination between the shallow donor level( sulfur vacancy) and the t2 level of Cu2 +. Besides,it is found that the photoluminescence intensity of Cu-doping NCs obviously increases with the concentration of Cu and reaches maximum at 0. 4at% because of concentration quenchment of Cu2 +.