催化劑輔助低溫化學氣相沉積合成二硒化錫之研究

Abstract

二維材料的領域日新月異，新興的材料與合成方法也不斷推陳出新。當中我們選擇熱電性質良好的二硒化錫作為研究對象，並且於先前研究中設計出以石墨烯催化低溫生長大面積、高品質的二硒化錫獲得極大成功。更低的生長溫度將降低生長時所需的能量消耗，以節約電能，並且有望使材料生長於低熔點的基板上。我們接續石墨烯催化的成功經驗，嘗試了以美耐皿海綿碳化形成的含氮多孔碳於低溫設置的化學氣相沉積合成法，沉積二硒化錫薄膜於熔融石英基板上。實驗結果顯示，由多孔碳催化的二硒化錫薄膜在100°C的溫度設置下有大面積及較好結晶。透過元素分析、拉曼光譜、吸收光譜及X射線光電子能譜確認了薄膜的成分為二硒化錫。而從原子力顯微鏡掃描中，我們發現催化生長出來的二硒化錫薄膜是多片單層二硒化錫結晶堆疊而成。 我們也檢驗了由此合成方式合成之二硒化錫薄膜的熱電性及在光偵測器的應用。在光偵測器應用中，由此方法合成之二硒化錫薄膜因其特殊的多層結構使其有著較低的載子遷移率，而有了很高的光響應率，這個高的光響應率優於多數的二硒化錫研究，並且是在低溫情況下的出最好的結果。 最後，由於生長出來的二硒化錫薄膜是多片單層二硒化錫結晶堆疊而成，可以預期在受到外應力導致形變時，層與層之間的距離將發生改變，進而影響電阻值，此一特性有望作為壓力應變計使用。由於壓力應變計需要使用可撓性的基板，我們將可以使用的低溫催化生長方法可以使二硒化錫薄膜生長在可撓玻璃上，並且在後續的實驗中成功證實了其電阻的可變性。由於催化生長的環境溫度較低，可以期望未來將二硒化錫薄膜生長在更加便宜且低熔點的可撓基板上，例如 : PET等塑膠基板。

The field of two-dimensional materials is evolution fast and new materials and synthesis methods are constantly being introduced. Among them, we chose tin diselenide, which has good thermoelectric properties, as the research object. In the previous research, we designed a large-area, high-quality tin diselenide catalyzed by graphene at low temperatures and got great success. Lower growth temperature will reduce the energy consumption required for growth to save electricity. It also gives us the possibility to make materials grow on a low-melting point substrate. Continuing the successful experience of graphene catalysis, we tried the chemical vapor deposition synthesis method of nitrogen-riched porous carbon formed by the carbonization of melamine sponge at low temperature, and deposited tin diselenide thin film on the fused quartz substrate. The experimental results show that the tin diselenide thin film catalyzed by porous carbon has a large area and better crystallization under the temperature setting of 100oC. Through elemental analysis, Raman spectroscopy, absorption spectroscopy, and X-ray photoelectron spectroscopy, it was confirmed that the composition of the film was tin diselenide. From the scanning of the atomic force microscope, we found that the tin diselenide film grown by catalysis is stacked with multiple single-layer tin diselenide crystals. We also examined the thermoelectric properties of the tin diselenide film synthesized by this new method and its application in photodetectors. In the application of photodetectors, the tin diselenide thin film synthesized by this method has a low carrier mobility due to its special multilayer structure and high photoresponsivity. This high photoresponse is better than most of the tin diselenide research, and it is the best result at low temperatures. Finally, since the synthesized tin diselenide thin film is composed of stacking multiple single-layer tin diselenide crystals, when the external stress causes deformation, the distance between the layers will change and affect the resistance value. This feature may be used as a pressure strain gauge. Since the pressure strain gauge needs to use a flexible substrate, we will use the low-temperature catalytic growth method to grow the tin diselenide film on the flexible glass, and successfully confirm the variability of its resistance in subsequent experiments. Due to the low synthesis temperature of the material growth, we may make tin diselenide thin films grown on flexible substrates with cheaper and lower melting points in the future, such as plastic substrates such as PET.