Header imagehome_title


Our group is interested in experimental research on novel semiconductor materials. Our focus is on synthesizing novel semiconductor epitaxy and nano-structures, and exploring their structural, electronic and optical properties for the applications in modern photonic devices. III-Nitrides such as GaN, AlN, InN and their alloys, and II-VI materials such as ZnO are our current focus. These materials are promising for the applications in the development of photonic devices such as light emitters and detectors. Chemical Vapor Deposition (CVD) technique is employed for the controlled growth of high quality materials. Materials are characterized by various techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), x-ray diffraction (XRD), photoluminescence (PL), Hall-effect measurement etc. We aim to fabricate multifunctional devices based on these materials.
   

Publications

50.   “Deep acceptor levels in phosphor and arsenic-doped zinc oxide epilayers”, B. Cai, M. L. Nakarmi, M. McMaster, N. Velpukonda, A. Smith, and T. N. Oder (submitted to Applied Physics Letter).
49 .   “Spin-Charge-Orbital Coupling in Multiferroic LuFe2O4 Thin Films”, R. C. Rai, A. Delmont, A. Sprow, B. Cai, and M. L. Nakarmi, Appl. Phys. Lett. 100, 212904 (2012)..
48.   “Elevated temperature dependence of energy band gap of ZnO thin films grown by E-Beam Deposition”, R. C. Rai, M. Guminia, S. Wilser, B. Cai, and M. L. Nakarmi, J. Appl. Phys. 111, 073511 (2012)
47.   “Three-step growth method for high quality AlN epilayers”, M. L. Nakarmi, B. Cai, J. Y. Lin, and H. X. Jiang, Phys. Status Solidi A 209, 126-129 (2012).
46.   “Optical and electrical properties of NiFe2O4 and CoFe2O4 thin films” R. C. Rai, S. Wilser, M. Guminiak, B. Cai, and M. L. Nakarmi, Applied Physics A, 104, (2011).
45.   “TEM Analysis of Microstructures of AlN/sapphire grown by MOCVD”, Bo Cai, and Mim L. Nakarmi, Mater. Res. Soc. Symp. Proc. 1202, I05 (2010).
44.   “Photoluminescence studies of impurity transitions in Mg-doped AlGaN alloys"  M. L. Nakarmi, N. Nepal, J. Y. Lin, and H. X. Jiang, Appl. Phys. Lett. 94, 091903 (2009).
43.   “ZnO thin film deposition on sapphire substrates by chemical vapor deposition”, Zhuo Chen, T. Salagaj, C. Jenson, K. Strobl, Mim Nakarmi, and Kai Shum, Mater Res. Soc. Symp. Proc. 1167, O07-09 (2009).
42.   “ZnO nanostructures epitaxially grown on ZnO seeded Si (100) substrates by chemical vapor deposition”, Zhuo Chen, T. Salagaj, C. Jenson, K. Strobl, Mim Nakarmi, and Kai Shum, Mater Res. Soc. Symp. Proc. 1178, AA06-21 (2009).
41.   Two-photon absorption induced photoluminescence in a ZnO nanostructure”, Zhuo Chen, T. Salagaj, C. Jenson, K. Strobl, V. Hongpinyo, Boon Ooi, Mim Nakarmi, and Kai Shum, Mater Res. Soc. Symp. Proc. 1178, AA09-13 (2009).
40.   "Photoluminescence properties of AlN homoepilayers with different orientations " A. Sedhain, N. Nepal, M. L. Nakarmi, T. M. Al tahtamouni, J. Y. Lin, H. X. Jiang, Z. Gu, and J. H. Edgar, Appl. Phys. Lett. 93, 041905 (2008).
39.   “Correlation between biaxial stress and free exciton transition in AlN epilayers”, B. N. Pantha, N. Nepal, T. M. Al Tahtamouni, M. L. Nakarmi, J. Li, J. Y. Lin, and H. X. Jiang, Appl. Phys. Lett. 91, 121117 (2007).
38.   “Correlation between optoelectronic and structural properties and epilayer thickness of AlN”
B. N. Pantha, R. Dahal, M. L. Nakarmi, N. Nepal, J. Li, J. Y. Lin, H. X. Jiang, Q. S. Paduano, and David Weyburne, Appl. Phys. Lett. 90, 241101 (2007).
37.   “200 nm deep ultraviolet photodetectors based on AlN”, J. Li, Z. Y. Fan, R. Dahal, M. L. Nakarmi, J. Y. Lin, and H. X. Jiang, Appl. Phys. Lett. 89, 213510 (2006).
36.   "Growth and photoluminescence studies of Zn-doped AlN epilayers," N. Nepal, M. L. Nakarmi, H. U. Jang, J. Y. Lin, and H. X. Jiang, Appl. Phys. Lett. 89, 192111 (2006).
35.   “Correlation between optical and electrical properties of Mg-doped AlN epilayers”. M. L. Nakarmi, N. Nepal, C. Ugolini, T. M. Altahtamouni, J. Y. Lin, and H. X. Jiang, Appl. Phys. Lett. 89, 152120 (2006).
34.   “Photoluminescence studies of impurity transitions in AlGaN alloys”. N. Nepal, M. L. Nakarmi, J. Y. Lin, and H. X. Jiang, Appl. Phys. Lett. 89, 092107 (2006).
33.   "Higher lying conduction band in GaN and AlN probed by photoluminescence spectroscopy," N. Nepal, K. B. Nam, J. Li, M. L. Nakarmi, J. Y. Lin, and H. X. Jiang, Appl. Phys. Lett. 88, 261919 (2006).
32.   “Deep ultraviolet photoluminescence studies of AlN photonic crystals”. N. Nepal, J. Shakya, M. L. Nakarmi, J. Y. Lin, and H. X. Jiang, Appl. Phys. Lett. 88, 133113 (2006).
31.   “Time-resolved photoluminescence studies of Mg-doped AlN epilayers”. N. Nepal, M. L. Nakarmi, J. Y. Lin, and H. X. Jiang, Proc. SPIE, 6118, 61180E (2006).
30.   “AlGaN/GaN/AlN quantum-well field-effect transistors with highly resistive AlN epilayers”. Z. Y. Fan, J. Li, M. L. Nakarmi, J. Y. Lin, and H. X. Jiang, Appl. Phys. Lett. 88, 073513 (2006).
29.   “Exciton localization in AlGaN alloys”. N. Nepal, J. Li, M. L. Nakarmi, J. Y. Lin, and H. X. Jiang, Appl. Phys. Lett. 88, 062103 (2006).
28.   "Stress Evolution during the Early Stages of AlN Vapor Growth", B. Wu, J. Bai, V. L. Tassev, M. Lal Nakarmi, W. Sun, X. Huang, M. Dudley, H. Zhang, D. F. Bliss, J. Lin, H. Jiang, J. Yang, and M. Asif Khan, Mater. Res. Soc. Symp. Proc. Vol. 892, 0892-FF26-01.1 (2006)
27.   “Temperature and compositional dependence of the energy bandgap of AlGaN alloys”. N. Nepal, J. Li, M. L. Nakarmi, J. Y. Lin, and H. X. Jiang, Appl. Phys. Lett. 87, 242104 (2005).
26.   “Unintentionally doped n-type Al0.67Ga0.33N epilayers”. M. L. Nakarmi, N. Nepal, J. Y. Lin, and H. X. Jiang. Appl. Phys. Lett. 86, 261902 (2005).
25.   “Deep impurity transitions involving cation vacancies and complexes in AlGaN alloys”. K. B. Nam, M. L. Nakarmi, J. Y. Lin, and H. X. Jiang, Appl. Phys. Lett. 86, 222108 (2005).
24.   “Electrical and optical properties of Mg doped Al0.7Ga0.3N alloys”. M. L. Nakarmi, K. H. Kim, M. Khizar, Z. Y. Fan, J. Y. Lin, and H. X. Jiang. Appl. Phys. Lett. 86, 092108 (2005).
23.   “AlGaN-based ultraviolet Light-emitting diodes grown on AlN epilayers”. K. H. Kim, Z. Y. Fan, M. Khizar, M. L. Nakarmi, J. Y. Lin, and H. X. Jiang. Appl. Phys. Lett. 85, 4777 (2004).
22.   “Silicon doping dependence of highly conductive n-type Al0.7Ga0.3N epilayers”. K. Zhu, M. L. Nakarmi, K. H. Kim, J. Y. Lin, and H. X. Jiang. Appl. Phys. Lett. 85, 4669 (2004).
21.   “Mg doped Al-rich AlGaN alloys for deep UV Emitters”. M. L. Nakarmi, K. H. Kim, K. Zhu, J. Y. Lin, and H. X. Jiang. Proc. SPIE Int. Soc. Opt. Engg. 5530, 54 (2004).
20.   “Band-edge exciton states in AlN single crystals and epitaxial layers”. L. Chen and B. J. Skromme, R. F. Dalmau, R. Schlesser, and Z. Sitar, C. Chen, W. Sun, J. Yang, and M. A. Khan, M. L. Nakarmi, J. Y. Lin, and H. X. Jiang, Appl. Phys. Lett. 85, 4334 (2004).
19.   “Transport properties of highly conductive n-type Al-rich AlxGa1-xN (x ³ 0.7)”. M. L. Nakarmi, K. Zhu, K. H. Kim, J. Y. Lin, and H. X. Jiang. Appl. Phys. Lett. 85, 3769 (2004).
18.   “Acceptor-bound exciton transition in Mg-doped AlN epilayer”. N. Nepal, M. L. Nakarmi, K. B. Nam, J. Y. Lin, and H. X. Jiang. Appl.Phys. Lett. 85, 2271, (2004).
17.   “Time-Resolved Photoluminescence Studies of Si & Mg-doped AlN epilayers”. K. B. Nam, M. L. Nakarmi, J. Y. Lin, and H. X. Jiang, Proceeding of SPIE, 5352, pp188 (2004).
16.   “Unique optical properties of AlGaN alloys and related ultraviolet emitter”. K. B. Nam, J. Li, M. L. Nakarmi, J. Y. Lin, and H. X. Jiang, Appl.Phys. Lett. 85, 5264 (2004).
15.   “Delta-doped AlGaN/GaN Heterostructure Field-Effect Transistors with Incorporation of AlN Epilayers”. Z. Y. Fan, M. L. Nakarmi, J. Y. Lin, and H. X. Jiang, Symposium Proceeding, Material Research Society 798, pp101, (2004).
14.   “Optical properties of the nitrogen vacancy in AlN epilayers”. N. Nepal, K. B. Nam, M. L. Nakarmi, J. Y. Lin, and H. X. Jiang, Appl. Phys. Lett. 84, 1090 (2004).
13.   “Band structure and fundamental optical transitions in wurzite AlN”. J. Li, K. B. Nam, M. L. Nakarmi, J. Y. Lin, and H. X. Jiang, Appl. Phys. Lett. 83, 5163 (2003).
12.   “Transition metal ion implantation into AlGaN”. R. M. Frazier, G. T. Thaler, C. R. Abernathy, and S. J. Pearton; M. L. Nakarmi, K. B. Nam, J. Y. Lin, and H. X. Jiang; J. Kelly, R. Rairigh, and A. F. Hebard,; J. M. Zavada; and R. G. Wilson. J. Appl. Phys., 94, 4956 (2003).
11.   “Photoluminescence studies of Si-doped AlN epilayers”. K. B. Nam, M. L. Nakarmi, J. Li, J. Y. Lin, and H. X. Jiang. Appl. Phys. Lett. 83, 2787 (2003).
10.   “Mg acceptor level in AlN probed by deep ultraviolet photoluminescence”. K. B. Nam, M. L. Nakarmi, J. Li, J. Y. Lin, and H. X. Jiang. Appl. Phys. Lett. 83, 878 (2003).
9.     “Properties of Co-,Cr-,or Mn-implanted AlN”. R. M. Frazier, J. Stapleton, G. T. Thaler, C. R. Abernathy, and S. J. Pearton; R. Rairigh , J. Kelly, and A. F. Hebard; M. L. Nakarmi, K. B. Nam, J. Y. Lin, and H. X. Jiang; J. M. Zavada; and R. G. Wilson. J. Appl. Phys., 94, 1592 (2003).
8.     “Epitaxial growth and time-resolved photoluminescence studies of AlN epilayers”. K. B. Nam, J. Li, M. L. Nakarmi, J. Y. Lin, and H. X. Jiang Proc. SPIE Int. Soc. Opt. Eng. 4992, 202 (2003).
7.     “Enhanced p-type conduction in GaN and AlGaN by Mg-d-doping”. M. L. Nakarmi, K. H. Kim, J. Li, J. Y. Lin, and H. X. Jiang. Appl. Phys. Lett. 82, 3041 (2003).
6.     “Deep ultraviolet picosecond time-resolved photoluminescence studies of AlN epilayers”. K. B. Nam, J. Li, M. L. Nakarmi, J. Y. Lin, and H. X. Jiang. Appl. Phys. Lett. 82, 1694 (2003).
5.     “Time-resolved photoluminescence studies of Al-rich AlGaN alloys”. J. Li, K. B. Nam, T. N. Oder, K. H. Kim, M. L. Nakarmi, J. Y. Lin, and H. X. Jiang. Proc. SPIE Int. Soc. Opt. Eng. 4643, 250 (2002).
4.     “Band-edge photoluminescence of AlN epilayers”. J. Li, K. B. Nam, M. L. Nakarmi, J. Y. Lin, and H. X. Jiang. Appl. Phys. Lett. 81, 3365 (2002).
3.     “Growth and optical studies of two-dimensional electron gas of Al-rich AlGaN/GaN heterostructures”. K. B. Nam, J. Li, M. L. Nakarmi, J. Y. Lin, and H. X. Jiang. Appl. Phys. Lett. 81, 1809 (2002).
2.     “Achieving highly conductive AlGaN alloys with high Al contents”. K. B. Nam, J. Li, M. L. Nakarmi, J. Y. Lin, and H. X. Jiang. Appl. Phys. Lett. 81, 1038 (2002).

1. “Optical and electrical properties of Mg-doped p-type AlxGa1-xN”. J. Li, T. N. Oder, M. L. Nakarmi, J. Y. Lin, and H. X. Jiang. Appl. Phys. Lett. 80, 1210 (2002).