进行了有机紫外半导体 N-[5-甲基-1,3,4-噻二唑-2-取代]二硫代氨基甲酸钾(PMTC)的制备及 FT-IR、Raman、UV-Vis及 PL光谱实验表征。对实验测试 FT-IR及 Raman光谱的振动峰进行了归属， Raman光谱测试发现 S-K在 152 cm-1有 v(S-K-S)伸缩振动。UV-Vis实验光谱表明 PMTC在 200～350 nm波段有紫外吸收， PL实验光谱表明 PMTC在 340～400 nm波段有明显的紫外发光峰，峰值波长为 373 nm，PL谱相对于吸收光谱有 Stokes频移。采用密度泛函理论(DFT)方法对 PMTC进行了 B3LYP/6-31G水平上的分子结构优化、UV-Vis光谱、分子前线轨道、分子电子密度、 Mulliken电荷等理论计算。理论研究结果表明： PMTC在 UV-Vis波段有三个电子跃迁吸收。前线轨道计算表明 PMTC的 HOMO的电子主要分布在与 K原子相连的两个 S原子上，而 LUMO轨道的电子主要集中在 K原子上，PMTC吸收光子后，产生电子由 HOMO至 LUMO跃迁的实质是电子由配体(主要是配位 S原子)向金属原子 K的转移。

Organic UV semiconductor Potassium (5-methyl-1,3,4-thiadiazol-2-yl) carbamodithioate (PMTC) has been prepared and experimentally characterized by FT-IR, Raman, UV-Vis and PL spectra. The vibrational peaks in FT-IR and Raman experimental spectra have been assigned. Raman spectrum shows that S-K has a stretching vibration v(S-K-S) at 152.3cm-1. The experimental UV-Vis spectrum indicates that PMTC has an UV absorption in 200-350nm range, the experimental PL shows an obvious UV emission peak in 340-400 range centered at 373nm, the Stokes shift has been observed. The geometry optimization, UV-Vis spectrum, frontier molecular orbitals, electron density as well as Mulliken charges calculations on PMTC have been carried out by using Density Functional Theory (DFT) at B3LYP/6-31G level. Theoretical research results show that PMTC has three electron transition absorptions in UV-Vis band. The frontier molecular orbital calculation on PMTC indicates that for HOMO, electron mainly locates at S atoms which bonded with K atom, as for LUMO, electron mainly locates at K atom. When PMTC absorbs photon, the essence of electron transition from HOMO to LUMO is the electron transfer from ligand(mainly is coordination S atom) to metal atom K.