火焰原子吸收法测定CdSe薄膜晶体管中Cd与Se的化学组成质量比

比特纯CdSe为标样，用火焰原子吸收法（FAAS），分别测定CdSe薄膜晶体管（TFT）中Cd与Se的含量及化学组成质量比，分别验证了CdSe粉末总量测定值，CdSe粉末化学组成质量比测定值，薄膜样品测定值的准确度，其相对误差分别为0．42％－3．8％和－0．5％。分析了薄膜样品化学组成质量比及影响其匹配的因素。通过测定数据对TFT的质量提供评价，进而指导操作工艺的改进。本实验由于采用同一标样，被测物质与标准样品的组成和浓度基本相同，消除了元素间的相互干扰，提高了分析结果的准确度，并无需作干扰和回收率实验。

Determination of Mass Ratio of Chemical Composition in CdSe Thin Film Transistors by FAAS

An FAAS method for the determination of mass ratio of chemical composition in thin film transistors ( TFT ) of CdSe is proposed in this paper. Pure CdSe was used as common standard sample of Cd and Se in the separate experiment. Measured value of total weight and mass ratio of chemical composition for CdSe powder,and measured value of TFT film sample were tested separately in order to check the accuracy of this method. Their relative errors are 0.42%,-3.8% and -0.5%,respectively. The results show that this method can meet the need of accuracy. Because disturbing effects between two elements are eliminated in the determination process using a common standard sample,the accuracy of determination with this method is better than that using two different standard samples. Disturbance and recovery experiments are not necessary to do because both sample and standard are the same approximately in component and concentration. Quality and influence factors of CdSe TFT can be explained by measured value. If measured weight of CdSe matches formula weight,then the operation sequences are rational and the quality of thin film is better (shown by the results of Sample a #). As pressure of saturated vapor of Se is higher than that of Cd,Se is more volatilizable than Cd. Concentration of Se in CdSe powder left over evaporating dish is decreased with increasing times of film deposition. The samples of 3 #?4 # are typical examples. Analytic results have proved this conclusion.