臺灣博碩士論文加值系統

本實驗利用物理汽相沉積法(PVD)，並藉由控制粉末端和基板端的溫度，以成長α相碘化汞多晶薄膜。由掃瞄式電子顯微鏡(SEM)與X-ray繞射(XRD)實驗來探討薄膜的表面形貌與結晶度。在電性量測方面，藉由熱誘發電流(TSC)量測來分析α相碘化汞多晶薄膜的載子捕捉能階和捕捉機制。另外，經由變溫的光電導頻譜，觀察α相碘化汞多晶薄膜能隙隨溫度的變化情形。最後，利用室溫附近的持續性光電導(PPC)量測來探討電流衰減的行為與機制。

In this study, by controlling the temperatures of the source powder side and of the substrate side, α-HgI2 polycrystalline films are prepared by physical vapor deposition (PVD). The surface morphology and the degree of crystallinity of the as-grown α-HgI2 polycrystalline films are characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), Respectively. For electrical properties, thermally stimulated current (TSC) measurements are performed to reveal the characters of deep-trapping levels. Furthermore, the temperature dependence of band gap deduced from photoconductivity (PC) spectra is measured, and the persistent photoconductivity (PPC) decay is studied.

目錄
中文摘要……………………….......….……………….…………..……….I
英文摘要……………………………….……………………………..……II圖目錄……….……………………….….…….……………………..…....Ⅳ表目錄…………………………………………………………………………..Ⅵ
1. 簡介………….…………………………...……………………………..1
2. 實驗與方法……………………….…………..……………………...…..5
2.1 實驗裝置…….………………………..….…….…………………..5
2.2 實驗配置...........................................................................................6
2.2.1 成長條件……………………..…….….…….....……………....6
2.2.2 實驗步驟………………………..….….…………….…………9
2.3 X-ray 繞射分析……………….……….…….… .……………….....9
2.4 熱誘發電流量測……………...…………..………….….…………10
2.5 光電導量測…………………………………………………………….10
2.6 持續性光電導量測……………………………………………...……..12
3. 結果與討論……………………………………………….……………16
3.1 薄膜表面形貌與成長條件…………………………………………16
3.2 XRD ( X-ray diffraction )分析……...……………………..………...17
3.3 熱誘發電流( Thermally stimulated current, TSC )量測……...……....20
3.4 光電導( Photoconductivity, PC )量測………………..…………..….35
3.5 持續性光電導( Persistent photoconductivity, PPC )………………...40
4. 結論……………………………………………………………………46
附錄………………...………………...……………………………………48
參考文獻……………………………………………………….………54


圖目錄

圖1 、碘化汞多晶薄膜成長系統示意圖； ( 1 ) 基板和基座 ; ( 2 ) α-HgI2粉末 ; ( 3 ) 溫控裝置; ( 4 ) 基座溫度計; ( 5 ) 溫度曲線 ; ( 6 ) 機械幫浦 ; ( 7 ) 真空計 ; ( 8 ) 過濾裝置。………………..7
圖2、PC、PPC與TSC量測系統示意圖。…………………………..11
圖3、α-HgI2多晶薄膜量測用三明治樣品示意圖。………………….13
圖4、光電導、持續性光電導以及熱誘發電流量測，光源打至α-HgI2多晶薄膜位置示意圖。…………………………………….…...14
圖5、俯視圖與側視圖:( a )-( e )分別對應Type A-E的α-HgI2多晶薄膜。………………………………………………………………18
圖6、Type A-E的α-HgI2多晶薄膜之XRD特性圖。……………...19
圖7、TSC量測時所使用的四種不同升溫速率之曲線圖。………...21
圖8、Type A的α-HgI2多晶薄膜之四種不同升溫速率下的TSC量測圖，其中升溫速率為1 K/min之TSC圖另被放大五倍。..….22
圖9、Type B的α-HgI2多晶薄膜之四種不同升溫速率下的TSC量測圖，其中升溫速率為1 K/min之TSC圖另被放大五倍。...…23
圖10、Type C的α-HgI2多晶薄膜之四種不同升溫速率下的TSC量測圖，其中升溫速率為1 K/min之TSC圖另被放大五倍。...…24
圖11、Type D的α-HgI2多晶薄膜之四種不同升溫速率下的TSC量測圖，其中升溫速率為1 K/min之TSC圖另被放大五倍。…..25
圖12、Type E的α-HgI2多晶薄膜之四種不同升溫速率下的TSC量測圖，其中升溫速率為1 K/min之TSC圖另被放大五倍。…..26
圖13、 更換矽感應器前後，Type D之不同樣品在升溫速率為30 K/min的TSC圖。…………………………………………………….28
圖14、Type A-E的α-HgI2多晶薄膜之80K的PC頻譜圖，抽真空下量測。…………………………………………………………..38
圖15、Type A-E的α-HgI2多晶薄膜之260K-297K的PC頻譜圖，抽真空下量測。…………………………………………………..39
圖16、Type A-E的α-HgI2多晶薄膜之290K-327K的PC頻譜圖，在大氣中量測。……………………….………………………….41
圖17、Type A-E樣品的PPC量測260K-297K之τ vs. 1000/T圖。……………………………………………………………..44
圖18、Type A-E樣品的PPC量測290K-327K之τ vs. 1000/T圖。……………………………………………………………..45

表目錄

表I. α-HgI2之物理特性表………………………….………………...….2
表II. 各Type成長條件表與成長速率以及晶粒大小。……..…...…....8
表III. 各Type之TSC缺陷能階統整表。………………………..……32
表IV. 其他文獻之TSC缺陷能階統整表。……………………….......33
表Ⅴ. 各Type在不同升溫速率下之TSC缺陷密度統整表( 1/cm3 )…36

1.F. Ayres, L. V. C. Assali, W. V. M. Machado and J. F. Justo, A first principles investigation of mercuric iodide: bulk properties and intrinsic defects, Braz. J. Phys. 34, 681 (1995).
2.J. E. Baciak and Z. He, Comparison of 5 and 10mm thick HgI2 pixelated g-ray spectrometers, Nucl. Instrum. Methods. A 505, 191 (2003).
3.P. Tyagi, and A. G. Vedeshwar, Anisotropic optical band gap of (102)-and (002)-oriented films of red HgI2, Phys. Rev. B 63, 245315 (2001).
4.S. L. Sharma, T. Pal and H. N. Acharya, A complete characterization of trapping levels in red mercuric iodide single crystals, J. Appl. Phys. 75, 7891 (1994).
5.X. J. Bao, T. E. Schlesinger, R. B. James, G. L. Gentry, A. Y. Cheng and C. Ortale, Study of semitransparent palladium contacts on mercuric iodide by photoluminescence spectroscopy and thermally stimulated current measurements, J. Appl. Phys. 69, 4247 (1991).
6.U. N. Roy, Y. Cui, G. Wright, C. Barnett, A. Burger, L. A. Franks and Z. W. Bell, Polycrystalline mercuric iodide films: deposition, properties, and detector performance, IEEE Trans. Nucl. Sci. 49, 1965 (2002).
7.S.O. Kasap and J.A. Rowlands, Direct-conversion flat-panel X-ray image detectors, IEE Proc.-Cirarits devices Syst. 149, 85 (2002).
8.R. Turchetta, W. Dulinski, D. Husson, J.L. Riester, M. Schieber, A. Zuck, L. Melekhov, Y. Saado, H. Hermon and J. Nissenbaum, Imaging with polycrystalline mercuric iodide detectors using VLSI readout, Nucl. Instrum. Methods. A 428, 88 (1999).
9.A. Zuck, M. Schieber, O. Khakhan and Z. Burshtein, Near single-crystal electrical properties of polycrystalline HgI2 produced by physical vapor deposition, IEEE Trans. Nucl. Sci. 50, 991 (2003).
10.J. P. Ponpon, R. Stuck and M. Amann, Current instability in mercuric iodide devices, Solid-State Electron. 44, 29 (2000).
11.H. Hermon, M. Schieber and M. Roth, Study of trapping levels in doped HgI2 radiation detectors, Nucl. Instrum. Methods. A 380, 10 (1996).
12.M. Piechotka and E. Kaldis,Vaporization study of mercury iodides HgI2 and Hg2I2, J. Less-Common Metals. 115,315 (1986).
13.J. Y. Lin, A. Dissanayake, G. Brown and H. X. Jiang, Relaxation of persistent photoconductivity in Al0.3Ga0.7As, Phys. Rev. B 42, 5855 (1990).
14.A. Dissanayake, M. elahi, H. X. Jiang and J. Y. Lin, Kinetics of persistent photoconductivity in Al0.3Ga0.7As and Zn0.3Cd0.7Se semiconductor alloys, Phys. Rev. B 45, 996 (1992).
15.D. V. Lang and R. A. Logan, Large-lattice-relaxation model for persistent photoconductivity in compound semiconductors, Phys. Rev. Lett. 39, 635 (1977).
16.K. C. Chiu, J. S. Wang, Y. T. Dai and Y. F. Chen, Anomalous temperature dependence of persistent photoconductivity in C60 single crystal, Appl. Phys. Lett. 69, 2665 (1996).
17.A. Dissanayake, J. Y. Lin and H. X. Jiang, Persistent photoconductivity in Zn0.04Cd0.96Se semiconductor thin films, Phys. Rev. B 48, 8145 (1993).
18.J. Y. Lin, A. Dissanayake and H. X. Jiang, Electric-field-enhanced Persistent photoconductivity in a Zn0.02Cd0.98Se semiconductor alloy, Phys. Rev. B 46, 3810 (1992).
19.D. Tromson, P. Bergonzo, A. Brambilla, C. Mer and F. Foulon, Thermally stimulated current investigations on diamond x-ray detectors, J. Appl. Phys. 87, 3360 (2000).
20.R. H. Bube, Opto-electronic properties of mercuric iodide, Phys. Rev. 106, 703 (1957).
21.T. Pal, S. L. Sharma and H. N. Acharya, A study of trapping levels in some red mercuric iodide single crystals for nuclear radiation detection, J. Phys. D 28, 1439 (1995).
22.R. Stuck, J. C. Muller, J. P. Ponpon, C. Scharager and C. Schwab, Study of trapping in mercuric iodide by thermally stimulated current measurements, J. Appl. Phys. 47, 1545 (1976).
23.P. Suryanarayana, H.N. Acharya and Y. F. Nicolau, Study of charge carrier trapping in solution-grown α-HgI2 crystals by thermally stimulated currents, Semicond. Sci. Technol. 7, 297 (1992).
24.莊博閔, 碘化汞晶體的熱激發電流頻譜分析, 中原大學應物所碩士論文, 中壢 (1995).
25.Y. Tsay, Y. S. Huang and Y. F. Chen, Photoconduction of synthetic pyrite FeS2 single crystals J. Appl. Phys. 74, 2786 (1993).
26.陳金源, 碘化汞單晶成長與特性量測, 中原大學應物所碩士論文, 中壢 (1993).
27.涂宏安, 碘化汞單晶成長與持續性光電導量測, 中原大學應物所碩士論文, 中
壢 (1998).
28.李政勳, 碘化汞晶體成長條件控制及其相關物性研究, 中原大學應物所, 中壢 (2000).
29.周漢唐, α相碘化汞電性及輻射偵測特性分析, 中原大學應物所, 中壢 (2002).
30.施誠琮, α相碘化汞多晶薄膜成長與物性分析, 中原大學應物所, 中壢 (2003).