Study of Polarons and Solitons on Quasi-One-Dimensional, Mixed Valence Platinum Complexes

卤素-桥接的、混合的valence白金复合体是一种类型的一类半导体。由intervalence charge transfer transition from Pt^<2+> to Pt^<4+\（CT\）。我们发现了两个新的吸收乐队，当CT乐队被激光兴奋时，中间间隙越来越近。这些光诱导的缺陷被包括在单链上的电子和孔极化对，通过测量光诱导的或卤素诱导的ESR和光学吸收特性。通过卤素掺杂，单电荷的极化通过过程P^++P^+ -> S^++S^+ （或BP^<2+>）产生并形成了可信电荷的同位素对（双极化）的形式，因此，发光特别研究到电子h重组的细节作为激发光子能量（E_X）和温度的函数。一项结果是，发光峰值转变将导致E_X在CT波段的低能量方面降低能量，但通常高于CT波段，因此，利用电子-H距离分布的帐户和波动性的温度依赖性。在房间温度下对纯和卤素掺杂晶体的瞬态光测量，显示E b方向（b ;链轴）中两个电子和孔的流动性，以及E b中的电子不能通过卤素掺杂而改变。However， the mobility of hole in the E b direction varies from 2 （pure） to 12 cm^2/V·sec （doped） in the iodine compound。这些结果导致了一个综合体，即polarons仅移动的运动温度， hole polarons被卤素注射，被掺杂的halogens被放置在中间和服务中心。

Halogen-bridged, mixed-valence Platinum complexes are typical quasi-one-dimensional semiconductors. The fundamental absorption is characterized by the intervalence charge transfer transition from Pt^<2+> to Pt^<4+> (CT band). We have found that two new absorption bands grow up near the midgap when the CT band is excited by laser. These photo-induced defects are concluded to be an electron and hole polarons pair on single chains by measuring the photo-induced or Halogen dope-induced ESR and optical absorption spectra. Upon halogen doping, singly charged polarons are produced and the formations of confined charged soliton pairs (bipolarons) via the process P^++P^+ -> S^++S^+ (or BP^<2+>) is favored.The luminescence spectra due to the e-h recombination are studied in details as function of the excitation photon energy (E_X) and temperature. One of results that the luminescence peak shifts to low energy with decreasing E_X at the low energy side of the CT band but is constant above the CT band, is well explained by taking account of the distribution of the e-h distance and the temperature dependence of the mobility of polarons. Transient photocurrent measurements in pure and halogen-doped crystals at room temperature show that the drift mobility of both electron and hole in the E b direction (b ; chain axis) and that of the electron in the E b do not change by halogen-doping. However, the mobility of hole in the E b direction varies from 2 (pure) to 12 cm^2/V・sec (doped) in the iodine compound. These results lead the conclusions that the polarons are mobile only athigh temperature, hole polarons are injected by halogen doping, the doped halogens are located on the interchains and serve as hopping centers.