Direct determination of the band offset in atomic layer deposited ZnO/hydrogenated amorphous silicon heterojunctions from X-ray photoelectron spectroscopy valence band spectra

被引：11

作者：

Korte, L. ^{[1
]}

Roessler, R. ^{[1
]}

Pettenkofer, C. ^{[1
]}

机构：

[1] Helmholtz Zentrum Berlin, Inst Silicon Photovolta, D-12489 Berlin, Germany

来源：

JOURNAL OF APPLIED PHYSICS | 2014年 / 115卷 / 20期

关键词：

SOLAR-CELLS; GAP STATES; INTERFACE; DENSITY; ENERGY; FILMS;

D O I：

10.1063/1.4879915

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

The chemical composition and band alignment at the heterointerface between atomic layer deposition-grown zinc oxide (ZnO) and hydrogenated amorphous silicon (a-Si:H) is investigated using monochromatized X-ray photoelectron spectroscopy. A new approach for obtaining the valence band offset Delta E-V is developed, which consists in fitting the valence band (VB) spectrum obtained for a-Si:H with a thin ZnO overlayer as the sum of experimentally obtained VB spectra of a bulk a-Si:H film and a thick ZnO film. This approach allows obtaining Delta E-V = 2.71 +/- 0.15 eV with a minimum of assumptions, and also yields information on the change in band bending of both substrate and ZnO film. The band offset results are compared to values obtained using the usual approach of comparing valence band edge-to-core level energy differences, Delta E-B,(CL) -Delta E-B,E-VB. Furthermore, a theoretical value for the VB offset is calculated from the concept of charge neutrality level line-up, using literature data for the charge neutrality levels and the experimentally determined ZnO/a-Si:H interface dipole. The thus obtained value of Delta E-V(CNL) = 2.65 +/- 0.3 eV agrees well with the experimental Delta E-V. (C) 2014 AIP Publishing LLC.

引用

页数：7

共 28 条

[1] Conversion efficiency and process stability improvement of electron beam crystallized thin film silicon solar cells on glass [J].

Amkreutz, D. ;

Haschke, J. ;

Haering, T. ;

Ruske, F. ;

Rech, B. .

SOLAR ENERGY MATERIALS AND SOLAR CELLS, 2014, 123 :13-16

[2] Microstructure and photovoltaic performance of polycrystalline silicon thin films on temperature-stable ZnO:Al layers [J].

Becker, C. ;

Ruske, F. ;

Sontheimer, T. ;

Gorka, B. ;

Bloeck, U. ;

Gall, S. ;

Rech, B. .

JOURNAL OF APPLIED PHYSICS, 2009, 106 (08)

[3] The effect of front ZnO:Al surface texture and optical transparency on efficient light trapping in silicon thin-film solar cells [J].

Berginski, Michael ;

Huepkes, Juergen ;

Schulte, Melanie ;

Schoepe, Gunnar ;

Stiebig, Helmut ;

Rech, Bernd ;

Wuttig, Matthias .

JOURNAL OF APPLIED PHYSICS, 2007, 101 (07)

[4] SEMICONDUCTOR INTERFACE FORMATION - THE ROLE OF THE INDUCED DENSITY OF INTERFACE STATES [J].

FLORES, F ;

MUNOZ, A ;

DURAN, JC .

APPLIED SURFACE SCIENCE, 1989, 41-2 :144-150

[5] Defects at the Si/SiO2 interface: their nature and behaviour in technological processes and stress [J].

Fuessel, W. ;

Schmidt, M. ;

Angermann, H. ;

Mende, G. ;

Flietner, H. .

Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1996, 377 (2-3) :177-183

[6] The silicon/zinc oxide interface in amorphous silicon-based thin-film solar cells: Understanding an empirically optimized contact [J].

Gerlach, D. ;

Wilks, R. G. ;

Wippler, D. ;

Wimmer, M. ;

Lozac'h, M. ;

Felix, R. ;

Mueck, A. ;

Meier, M. ;

Ueda, S. ;

Yoshikawa, H. ;

Gorgoi, M. ;

Lips, K. ;

Rech, B. ;

Sumiya, M. ;

Huepkes, J. ;

Kobayashi, K. ;

Baer, M. .

APPLIED PHYSICS LETTERS, 2013, 103 (02)

[7] DETERMINATION OF THE FERMI-LEVEL PINNING POSITION AT SI(111) SURFACES [J].

HIMPSEL, FJ ;

HOLLINGER, G ;

POLLAK, RA .

PHYSICAL REVIEW B, 1983, 28 (12) :7014-7018

[8] Interface formation of CuInSe2 (112) and ZnO deposited by atomic layer deposition [J].

Janocha, E. ;

Hofmann, A. ;

Pettenkofer, C. .

RADIATION PHYSICS AND CHEMISTRY, 2013, 93 :72-76

[9] ALD of ZnO using diethylzinc as metal-precursor and oxygen as oxidizing agent [J].

Janocha, E. ;

Pettenkofer, C. .

APPLIED SURFACE SCIENCE, 2011, 257 (23) :10031-10035

[10] Parameterization of the optical functions of amorphous materials in the interband region [J].

Jellison, GE ;

Modine, FA .

APPLIED PHYSICS LETTERS, 1996, 69 (03) :371-373

← 1 2 3 →