Abstract
The performances of second harmonic generation (SHG) and optical parametric oscillator (OPO) in CdGeAs2 crystal are strongly influenced by surface quality. In this paper, the surfaces of samples were treated by mechanical polishing (MP), chemical polishing (CP), chemical–mechanical polishing (CMP) and CP following CMP closely (CMP + CP). Then, the surface state was characterized by optical microscopy (OM), scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). AFM measurements show that an ultra-smooth surface is achieved after CMP + CP treatment and the roughness value is 0.98 nm. Meanwhile, the roughness of the surfaces treated by MP, CP and CMP are 4.53, 2.83 and 1.38 nm, respectively. By XRD rocking curves, the diffraction peak which belongs to the wafer treated by CMP + CP is the highest in intensity and best symmetrical in shape. XPS analysis indicates that Ge4+ proportions of GeO2 in total Ge content of CdGeAs2 wafers’ surface after MP, CP, CMP and CMP + CP treatment are 27.6%, 42.8%, 6.1% and 30.3%, respectively.
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References
Byer RL, Kildal H, Feigelson RS. CdGeAs2—a new nonlinear crystal phasematchable at 10.6 μm. Appl Phys Lett. 1971;19(7):237.
Nikogosyan DN. Nonlinear optics crystals (review and summary of data). Sov J Quantum Electron. 1977;7(1):5.
Iseler GW, Kildal H, Menyuk N. Optical and electrical properties of CdGeAs2. J Electron Mater. 1978;7(6):737.
Zlatkin LB, Markov YF, Stekhanov AI, Shur MS. The investigation of the vibrational spectrum, optical constants and ionicity of bond of CdGeAs2 in crystal and amorphous phases by I.R. reflection. J Phys Chem Solids. 1970;31(3):567.
Nikogosyan DN. Nonlinear optics crystals (review and summary of data). Sov J Quantum Electron. 1977;7(1):5.
Vodopyanova KL, Knippelsb GMH, van der Meerb AFG, Maffetonec JP, Zwiebackc I. Optical parametric generation in CGA crystal. Opt Commun. 2002;202:205.
Zakel A, Setzler SD, Shunemann PG, Pollak TM, Burky M, Guha S. Optical parametric oscillator based on cadmium germanium arsenide. Lasers Electro Opt. 2002;1:172.
Slater JC. Theory of the transition in KH2PO4. J Chem Phys. 1941;9(1):16.
Vodopyanov KL, Schunemann PG. Efficient difference-frequency generation of 7–20 μm radiation in CdGeAs2. Opt Lett. 1998;23(14):1096.
Andreev YM, Voevodin VG, Geĭko PP, Gribenyukov AI, Dyad’Kin AP, Pigul’Skiĭ SV, Starodubtsev AI. Efficient generation of the second harmonic of NH3 laser radiation in CdGeAs2. Sov J Quantum Electron. 1987;17(4):491.
Al-Saidi IA, Harrison RG. Wavelength Dependence of high-efficiency second-harmonic generation in CdGeAs2. Appl Phys B. 1985;36(1):17.
Harrison RG, Gupta P, Taghizadeh MR, Kar AK. Efficient multikilowatt mid infrared difference frequency generation in CdGeAs2. IEEE J Quantum Electron. 1982;18(8):1239.
Shen M, Zhang JJ, Wang L, Min J, Wang L, Liang X, Huang J, Tang K, Liang W, Meng H. Investigation on the surface treatments of CdMnTe single crystals. Mater Sci Semicond Process. 2015;31:536.
Nagashio K, Watcharapasorn A, Zawilskia KT, DeMattei RC, Feigelson RS, Bai L, Giles NC, Halliburton LE, Schunemann PG. Correlation between dislocation etch pits and optical absorption in CdGeAs2. J Cryst Growth. 2004;269(2–4):195.
Bai L, Poston JA Jr, Schunemann PG, Nagashio K, Feigelson RS, Giles NC. Luminescence and optical absorption study of p-type CdGeAs2. J Phys: Condens Matter. 2004;16(8):1279.
He ZY, Zhao BJ, Zhu SF, Li JW, Zhang Y, Du WJ, Huang W, Chen BJ. Preparation and characterization of CdGeAs2 crystal by modified vertical Bridgman method. J Cryst Growth. 2011;314(1):349.
Huang W, Zhao B, Zhu S, He Z, Chen B, Tang J, Liu W. Growth and characterizations of CdGeAs2 single crystal by descending crucible with rotation method. Rare Met. 2014;33(2):210.
Huang W, Zhao BJ, Zhu SF, He ZY, Chen BJ, Li JW, Yu Y. Studies of etching on CdGeAs2 crystals. J Synth Cryst. 2010;6(39):1349.
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This work was financially supported by the National Natural Science Foundation of China (No. 50732005) and the National High Technology Research and Development Program of China (No. 007AA03Z443).
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Huang, W., Zhao, BJ., Zhu, SF. et al. Surface treatments of CdGeAs2 single crystals. Rare Met. 38, 683–688 (2019). https://doi.org/10.1007/s12598-016-0818-0
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DOI: https://doi.org/10.1007/s12598-016-0818-0