トポロジカル絶縁体PbBi_2_Te_4_を出発物質とし、Sbを加えることによって絶縁化を図る。PbBi_2_Te_4_がn型半導体、Biを100％Sb置換すると

有機薄膜トランジスタ (OTFT) を集積した有機集積回路は，薄く，柔軟性があり，軽量であるといった，シリコン (Si) ベースの薄膜トランジスタ (TFT) では実現困難な特徴をもつ．また，有機集積回路は，銀ナノ粒子インクや有機半導体インク，絶縁体材料インクを用いた印刷法により作製が可能であり，その特性はマスク蒸着やフォトリソグラフィといった従来の作製プロセスを用いて作製された回路の性能に到達しようとしている．一般的に

Preciously, we suggested a novel heat-electric power conversion effect without temperature gradient. In this study, we purposed synthesizing sample for a novel effect with Spark Plasma Sintering (SPS). This effect needs joining n-type, intrinsic and p-type semiconductors. In addition, intrinsic semiconductor must have narrower band gap than n- and p-type semiconductors. Therefore, we payed attention to Ba₈Au_xSi_46-x for satisfying these requirements. Ba₈Au_xSi_46-x is changed its electrical properties by Au contents. Furthermore, this materials show that n- and p-type semiconductors show wider band gap than intrinsic semiconductor. In this study, we synthesized two layers sample of n-type and p-type Ba₈Au_xSi_46-x with SPS. Sintering process was expected promoting Au diffusing from p-type to n-type, and form a Au gradient part in n/p interface. According to results of WDX, chemical composition gradient was observed in n/p interface. This result showed that sample synthesized by SPS satisfied two requirements. Therefore, the sample was heated under uniform temperature and generated voltage showed 2.5 mV at 500°C. These results suggested SPS was suitable method for synthesizing samples of a novel effect.

NiO is a p-type semiconductor having a large band gap (> 3 eV). In this study, thin films containing Ni-O were deposited by the cathodic electrochemical deposition method, and characteristics change by heat treatment was investigated. An aqueous solution containing Ni(NO₃)₂ was used as a deposition solution. X-ray photoelectron spectroscopy showed that the sample before annealing was predominantly Ni(OH)₂. After heat treatment in air at temperatures higher than 300ºC, the NiO phase was observed by X-ray diffraction, and the p-type response was confirmed by the photoelectrochemical measurement. The band gap obtained from the light transmittance measurement was around 3.5eV.

酸化ガリウム(Ga_2_O_3_)はパワーデバイスへの応用が期待されている。しかしGa_2_O_3_の価電子帯頂上付近は分散が非常に小さいため、正孔ドープが難しく、

A novel electric power generation different from the Seebeck effect by using poly-crystaline Ba₈Au_xSi_46-x clathrate consisted of two layers, n-type and p-type materials, was devised. In order to investigate composition dependence of generated voltage, poly-crystalline clathrate samples consisted of two layers with various Au composition were prepared by SPS method. According to composition analysis, the mixed layer was formed at the interface of two layers. The sample consisted of n-type Ba₈Au_4.5Si_41.5 / p-type Ba₈Au_5.5Si_40.5 can generate around 2.0 mV at 723 K under no temperature difference. It is considered that this voltage was caused by charge separation with the diffuse of electrons and holes exited at mixed layer with narrower band gap part on interface. Ba₈Au_4.0Si_42.0 / Ba₈Au_6.0Si_40.0 and Ba₈Au_4.8Si_41.2 / Ba₈Au_5.2Si_40.8 samples showed around 4.0 and 1.0 mV at 723 K, respectively. These results suggested that the voltage increased with difference of Fermi level between n- and p-type semiconductors.