新型热电材料及其新应用

热电材料，由于在清洁能源、光电子探测等诸多方面有巨大的应用前景，因而受到科学上和技术上的广泛关注．最新的理论进展和若干新材料的发现，为人们提供了新的应用机会．一类新材料就是基于强关联电子系统，典型例子是过渡族金属氧化物，这类材料以前从热电材料的角度并未受到重视．我们将讨论几点最近的进展，着重讨论生长在倾斜切割衬底上薄膜的新的应用．这种情况下热电电压的产生是基于各向异性的塞贝克效应．当光辐射照射到薄膜表面时，薄膜上下表面的温差引起横向的电势差，从而可用于光、热辐射的探测．我们论证：这类探测器有很具特色的优点，宽的光谱响应，快的时间响应，同时不须施加偏压或偏流，因而十分节能．我们还讨论了几种典型材料的性能．

New Thermoelectric Materials and New Applications

Thermoelectricity in general is of strong scientific and technological interest due to its application possibilities ranging from clean energy to photo sensing devices. Recent development in theoretical studies on the thermoelectric effects, as well as the newly discovered thermoelectric materials provide new opportunities for wide applications. One type of these materials is based on the strongly correlated electron systems; typical examples are the transition metal oxides, which were not regarded as very promising for thermoelectric applications. A discussion is made on some recent progress in this field, and special emphasis is laid on the new application of thin films grown on vicinal cut substrates.The thermoelectric effect is based on the anisotropic Seebeek components in crystals. Upon radiation of heat and/or light on the film surface, there will be an induced voltage; hence a device which can detect the heat and/or light radiation can be made. It is pointed out that this type of detector demonstrates novel properties: broad optical response, very fast response and at the same time it does not need any bias, therefore it is extremely energy saving. The performances of three typical compounds YBa2Cu3O7-δ, LaCaMnO3 and LaSrCoO3 are presented.