Department of Materials Science and Engineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, Pennsylvania 19104, United States.
Nano Lett. 2011 Jul 13;11(7):2841-4. doi: 10.1021/nl2012246. Epub 2011 Jun 1.
This work demonstrates the first solution-processable metal-semiconductor nanocomposites with enhanced thermoelectric properties via carrier energy filtering. Platinum nanocrystals are embedded in a p-type antimony(III) telluride (Sb(2)Te(3)) semiconductor matrix, thus introducing band-bending potentials for holes. By scattering low energy holes, an increase in thermopower is observed. Introduction of Pt nanocrystals also increases carrier concentration thereby partially compensating for reduced electrical conductivity due to the decreased mobility. At room temperature, an improvement in thermoelectric power factor was achieved compared to that of the Sb(2)Te(3) films. This work highlights the possibility of combining a diverse set of n- and p-type semiconductor matrices with nanocrystals to engineer and optimize energy-dependent carrier scattering with the ease of materials processing.
这项工作展示了通过载流子能量过滤来提高热电性能的首例可溶液加工的金属-半导体纳米复合材料。铂纳米晶嵌入 p 型三碲化锑（Sb(2)Te(3)）半导体基体中，从而引入了空穴的能带弯曲势。通过散射低能量空穴，观察到了热电势的增加。铂纳米晶的引入也增加了载流子浓度，从而部分补偿了由于迁移率降低而导致的电导率降低。在室温下，与 Sb(2)Te(3)薄膜相比，热电功率因子得到了提高。这项工作突出了用纳米晶来工程化和优化与能量相关的载流子散射的可能性，同时易于材料加工，可以将多种 n 型和 p 型半导体基体结合在一起。
