【摘要】：納米尺度的PbS膠體量子點(diǎn)的能帶從近紅外區(qū)域藍(lán)移到可見光區(qū),這一特點(diǎn)使其呈現(xiàn)出與體相材料不同的光學(xué)性質(zhì)和電學(xué)性質(zhì),因而被廣泛應(yīng)用于非線性光學(xué)器件、紅外探測(cè)器以及太陽能電池等領(lǐng)域。這些器件一般可以通過摻雜來調(diào)整其載流子濃度。然而,實(shí)現(xiàn)PbS膠體量子點(diǎn)的穩(wěn)定摻雜目前仍然是一個(gè)挑戰(zhàn)。PbS膠體量子點(diǎn)在未經(jīng)摻雜處理時(shí)通常表現(xiàn)為p型,如果PbS膠體量子點(diǎn)可以有n型特性,就可以與p型的PbS膠體量子點(diǎn)組合來制備同質(zhì)結(jié),從而避免高溫?zé)Y(jié)制備TiO2電極以及很多因?yàn)闊Y(jié)所帶來的問題。同時(shí),同質(zhì)結(jié)也可以避免異質(zhì)結(jié)所產(chǎn)生的界面效應(yīng)。另外鈍化或摻雜還可以使量子點(diǎn)在呈現(xiàn)n型特性的同時(shí)擁有更好的電學(xué)性能。本文首先介紹了相關(guān)背景知識(shí)。包括量子點(diǎn)的基本概念及其物性,量子點(diǎn)摻雜的由來,目前發(fā)展的現(xiàn)狀以及所存在的問題;然后闡明了量子點(diǎn)合成以及摻雜鈍化的微觀機(jī)理;接著介紹了一種以硫化氫(H2S)氣體為硫源制備硫化鉛(PbS)量子點(diǎn)的方法,分析溫度和生長(zhǎng)時(shí)間對(duì)粒徑的影響;隨后詳細(xì)描述了陽離子置換法制備PbS膠體量子點(diǎn)以及后續(xù)四丁基碘化銨(TBAI)處理等摻雜過程。樣品測(cè)試和數(shù)據(jù)分析工作包括:通過紫外-可見吸收峰判斷粒子粒徑的變化;通過傅里葉變換紅外光譜判斷處理前后有機(jī)鍵的變化情況;運(yùn)用X射線衍射儀測(cè)試生成的PbS膠體量子點(diǎn)的結(jié)構(gòu)。根據(jù)上述測(cè)試所得數(shù)據(jù)分析量子點(diǎn)性能與合成條件的關(guān)系,不斷優(yōu)化實(shí)驗(yàn)方案,并最終制備出摻雜良好、性能優(yōu)異的單分散PbS膠體量子點(diǎn)。
[Abstract]:Nanoscale PbS colloidal quantum dots have been widely used in nonlinear optical devices due to their blue shift from near infrared region to visible region, which makes them exhibit different optical and electrical properties from bulk materials. Infrared detectors and solar cells and other areas. These devices can generally be doped to adjust their carrier concentration. However, it is still a challenge to achieve stable doping of PbS colloidal quantum dots. PBS colloidal quantum dots usually exhibit p-type when they are not doped. If PbS colloidal quantum dots can have n-type properties, It can be combined with p-type PbS colloidal quantum dots to prepare homogenous junctions, thus avoiding the preparation of TiO2 electrodes at high temperature and many problems caused by sintering. At the same time, the homogeneous junction can avoid the interface effect caused by the heterojunction. In addition, passivation or doping can make the quantum dots have better electrical properties as well as n-type properties. This paper first introduces the relevant background knowledge. It includes the basic concepts and physical properties of quantum dots, the origin of quantum dot doping, the current development and existing problems, and then expounds the micro mechanism of quantum dot synthesis and doping passivation. Then a method of preparing lead sulfide (PbS) quantum dots with hydrogen sulfide gas as sulfur source is introduced. The effects of temperature and growth time on particle size are analyzed. Then the doping process of PbS colloidal quantum dots prepared by cationic replacement method and subsequent four Ding Ji ammonium iodide (TBAI) treatment were described in detail. The work of sample testing and data analysis includes: the change of particle size is judged by UV-Vis absorption peak, the change of organic bond before and after treatment is judged by Fourier transform infrared spectroscopy (FTIR), and the change of organic bond is determined by Fourier transform infrared spectroscopy (FTIR). The structure of PbS colloidal quantum dots was measured by X ray diffractometer. According to the data obtained above, the relationship between the properties of quantum dots and the synthesis conditions was analyzed, and the experimental scheme was optimized. Finally, monodisperse PbS colloidal quantum dots with good doping and excellent performance were prepared.
【學(xué)位授予單位】：華中科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：O471.1

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本文編號(hào)：2168592