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The van der Pauw Method is a technique commonly used to measure the resistivity and the Hall coefficient of a sample. Its power lies in its ability to accurately measure the properties of a sample of any arbitrary shape, so long as the sample is approximately two-dimensional (i.e. it is much thinner than it is wide), solid (no holes), and the electrodes are placed on its perimeter. From the measurements made, the following properties of the material can be calculated: * The resistivity of the material * The doping type (i.e. whether it is a P-type or N-type material) * The sheet carrier density of the majority carrier (the number of majority carriers per unit area). From this the charge density and doping level can be found * The mobility of the majority carrier The method was first propounded by Leo J. van der Pauw in 1958.〔)〕 == Conditions == There are five conditions that must be satisfied to use this technique: 1. The sample must have a flat shape of uniform thickness 2. The sample must not have any isolated holes 3. The sample must be homogeneous and isotropic 4. All four contacts must be located at the edges of the sample 5. The area of contact of any individual contact should be at least an order of magnitude smaller than the area of the entire sample. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Van der Pauw method」の詳細全文を読む スポンサード リンク
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