Organic Semiconductor Compound Film Transport Properties And The Lateral Photovoltaic Effect

Recently, organic spintronics has attracted a lot of interest, and magnetoresistance effect has been observed in organic semiconductor hybrid films with different structures, which can be used in sensors and storage fields. Correspondingly, microelectronics and photon-electronics properties of inorganic semiconductor devices have been investigated extensively and have been used in application. In this thesis, the hybrid film samples have been prepared by depositing organic-semiconductor granular films on inorganic semiconductor substrates, and its transmission property and lateral photovoltage effect have been studied. The contents of this thesis are as follow:PART A:The transport properties in Co-Alq3 granular films on silicon structures.1. The Co-Alq3 granular film was deposited on silicon substrates with the native oxide layer (n type,<111>), forming the Co-Alq3/SiO2/Si structures.2. A crossover of magnetoresistance (MR) from negative to positive was observed in the samples, due to conducting channel switching. The transport properties of samples are greatly influenced by hydrofluoric acid pretreatment, as a result, positive MR decreases drastically and the temperature dependence of resistance changes a lot near room temperature. It indicates that the native oxide layer plays an important role in the transport mechanism. Moreover, different resistivities of Si substrates influence the current distribution of conducting channels, leading to different transport behaviors accordingly.PART B:Lateral Photovoltage in Co-Alq3 granular film on silicon substrate.1. The Co-Alq3 granular film were deposited on different kinds of silicon substrates (n type,<111>), forming the Co-Alq3/Si and Co-Alq3/SiO2/Si structures.2. Lateral photovoltaic effect was observed in Co-Alq3/Si and Co-Alq3/SiO2/Si. High-sensitivity lateral photovoltage was observed in Co0.4(Alq3)0.6/Si samples with good linearity, reaching 37.7mV/mm.3. The insert of native oxide layer results in the decrease of LPV. The dependence of lateral photovoltaic effect on substrates was also investigated.