退火对ZnS/PS复合体系光致发光特性的影响  

The Effect of Annealing on Photoluminescence Properties of ZnS/PS Composite System

作　　者：王彩凤[1] 李清山[1] 张立春[1] 吕磊[1] 齐红霞[1] 

机构地区：[1]曲阜师范大学物理工程学院,山东曲阜273165

出　　处：《发光学报》2007年第4期541-545,共5页Chinese Journal of Luminescence

基　　金：山东省自然科学基金资助项目(Y2002A09)

摘　　要：用脉冲激光沉积（PLD）技术以多孔硅（PS）为衬底生长了ZnS薄膜,分别测量了ZnS、PS以及ZnS/PS复合体系在室温下的光致发光（PL）光谱.结果发现,ZnS/PS复合体系的PL光谱中PS的发光峰位相对于新制备的PS有所蓝移.把该ZnS/PS样品分成三块,在真空400 ℃分别退火10,20,30 min,研究不同退火时间对ZnS/PS复合体系光致发光特性的影响.发现退火后样品的PL光谱中都出现了一个新的绿色发光带,归结为ZnS的缺陷中心发光.随着退火时间的延长,PS的发光强度逐渐降低且峰位红移.把ZnS的蓝、绿光与PS的红光相叠加,整个ZnS/PS复合体系在可见光区450～700 nm形成一个较宽的光致发光谱带,呈现较强的白光发射.The achievement of Si-based white light emission is one of the challenging goals in the field of display and lighting technologies. Generally, there are two methods to produce white light from light-emitting diodes （LEDs） ： combining three LED chips （red, green, and blue） in one discrete package or as a cluster LED chips, and coating blue indium-gallium-nitride （In-GaN） LED chips with phosphors. In addition, fabricating multilayer devices using different materials that emit lights with different colors, based on the principle of tricolor （red, green, and blue） overlay, white light can also be obtained. ZnS films were deposited on porous silicon （PS） substrate by pulsed laser deposition （PLD）, and the room-temperature photoluminescence spectra of ZnS films, PS and ZnS/PS composite system were measured. The results show that, after ZnS films were deposited, a blueshift of the red emission from PS layer occurs. Then the ZnS/PS sample was cut into three pieces, and annealed in vacuum at 400 ℃ for 10, 20 and 30 min respectively. In the PL spectra of the three annealed samples, there appeared a new green emission band located at about 550 nm compared with the PL spectra of ZnS/PS composite system before annealing ZnS. With the increase of annealing time, the intensity of , which is ascribed to the defect-center emission of the red emission from PS layer decreases, and a redshift of the peak occurs, which is attributed to the optical band gap shrinking of a-Si： H as a function of hydrogen loss during annealing. Combining the blue, green emission from ZnS films with the red emission from PS layers, a broad PL band from 450 nm to 700 nm in the visible region is obtained, exhibiting intensively white light emission. This work offers a cheap route for fabricating a white LED, which is significant for display and lighting technology.

关 键 词：光致发光 白光 退火 ZNS薄膜 多孔硅 

分 类 号：O484.41[理学—固体物理]