二維鈣鈦礦材料之光電性質及應用

Abstract

透過二步法先以溶液方式得到鈣鈦礦前驅物，接著以溶液及蒸汽方式轉換成鈣鈦礦並且對性質進行探究。我們對SnBr_2材料實驗平面、斜面以及旋塗等結晶方式，並為了改善其濃度嘗試利用混合溶劑，使得我們能夠得到較明顯的晶體，並在斜面法中得到較薄結晶。首先配置PbI_2 溶液搭配旋轉塗佈部機與熱風槍，實現在二氧化矽上能夠大量結晶出PbI_2單晶薄片，其厚度大多落於2nm至10nm之間，並在透過配置MAI溶液，將其旋塗至PbI_2 晶體上得到MAPbI_3之二維鈣鈦礦晶體。透過與過去文獻XRD特徵峰值對比能夠確認其二維鈣鈦礦身分，並且由PL圖譜能夠得知，由於量子侷限效應隨著厚度降低PL峰值會逐漸藍移，且隨著溫度的降低會產生紅移的特性。關鍵字：低維鈣鈦礦、碘化鉛、溴化亞錫Abstract Two perovskite precursors materials were investigated in this research：SnBr_2 and PbI_2,we use two step method to transfer SnBr_2 and PbI_2 to MAPbI_3 and MASnBr_3. We experimented with SnBr_2 materials such as plane, inclined plane and spin coating, and in order to improve it’s concentration, we tried to use mixed solvents, so that we could get more obvious crystals, and get thinner crystals in the inclined plane method. The solution synthesized by DI water and PBI2 powder can use spin coater and hot air gun to get many crystals on SiO_2 substrate, and the thickness is mostly between 2nm and 10nm. The two-dimensional perovskite crystal of MAPbI_3 is obtained by coating on PbI_2 crystal. The identity of the two-dimensional perovskite can be confirmed by comparing with the characteristic peaks of XRD in the past literature, and it can be seen from the PL spectrum that the PL peak will gradually blueshift as the thickness decreases due to the quantum confinement effect, and will produce redshift as the temperature decreases.Keywords: low dimensional perovskite, Lead(II) iodide, Tin(II) bromide