利用脈衝雷射蒸鍍法製備摻銅碲硒化鉍薄膜以及利用光激發中紅外探測光譜研究其超快載子動力學

Abstract

在本論文中，我們利用脈衝雷射蒸鍍法製備摻銅碲硒化鉍薄膜於藍寶石(0001)基板上；藉由X-ray 繞射儀(XRD)和拉曼光譜來探討改變製程溫度其薄膜品質的比較，經由紅外反射光譜研究其在中紅外波段的電磁特性以及由霍爾量測得到其載子濃度。由光激發-中紅外探測系統對Cu0.5Bi2Se1.5Te1.5晶體做量測並且觀察到谷間散射的訊號，接著由相同的系統再對最佳鍍膜條件的Cu0.5Bi2Se1.5Te1.5薄膜做量測，除了觀察到谷間散射的訊號外，我們亦觀察到另一種疑似表面態的訊號。

In this work, we have prepared Cu0.5Bi2Se1.5Te1.5 thin films were grown on sapphire(Al2O3)(0001) substrates by pulsed laser deposition(PLD) with various deposition temperatures. We analyzed their crystal structure and thin film quality by X-ray diffraction(XRD) and Raman spectroscopy. The physical properties in Cu0.5Bi2Se1.5Te1.5 thin films with various temperature conditions were studied by Fourier transform infrared spectroscopy(FTIR) and Hall measurement. We could find the intervalley scattering in Cu0.5Bi2Se1.5Te1.5 singal crystal by using optical pump mid-infrared probe spectroscopy(OPMP). Then we used the same system(OPMP) to measure the best condition of Cu0.5Bi2Se1.5Te1.5 thin film. And there was another signal suspected surface state signal.