{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T13:36:40Z","timestamp":1777556200015,"version":"3.51.4"},"reference-count":43,"publisher":"AIP Publishing","issue":"20","funder":[{"name":"Excellence Cluster Nanosystems Initiative Munich"},{"name":"TUM.solar in the frame of the Bavarian Collaborative Research Project"}],"content-domain":{"domain":["pubs.aip.org"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2017,5,28]]},"abstract":"<jats:p>In this work, we use conductance and contact potential difference photo-transient data to study the influence of the growth technique, doping, and crystal polarity on the kinetics of photo-generated charges in GaN. We found that the processes, and corresponding time scales, involved in the decay of charge carriers generated at and close to the GaN surface via photo-excitation are notably independent of the growth technique, doping (n- and p-types), and also crystal polarity. Hence, the transfer of photo-generated charges from band states back to surface states proceeds always by hopping via shallow defect states in the space-charge region (SCR) close to the surface. Concerning the charge carrier photo-generation kinetics, we observe considerable differences between samples grown with different techniques. While for GaN grown by metal-organic chemical vapor deposition, the accumulation of photo-conduction electrons results mainly from a combined trapping-hopping process (slow), where photo-generated electrons hop via shallow defect states to the conduction band (CB), in hydride vapor phase epitaxy and molecular beam epitaxy materials, a faster direct process involving electron transfer via CB states is also present. The time scales of both processes are quite insensitive to the doping level and crystal polarity. However, these processes become irrelevant for very high doping levels (both n- and p-types), where the width of the SCR is much smaller than the photon penetration depth, and therefore, most charge carriers are generated outside the SCR.<\/jats:p>","DOI":"10.1063\/1.4983846","type":"journal-article","created":{"date-parts":[[2017,5,25]],"date-time":"2017-05-25T14:55:24Z","timestamp":1495724124000},"update-policy":"https:\/\/doi.org\/10.1063\/aip-crossmark-policy-page","source":"Crossref","is-referenced-by-count":9,"title":["Photo-induced changes of the surface band bending in GaN: Influence of growth technique, doping and polarity"],"prefix":"10.1063","volume":"121","author":[{"given":"Andrea","family":"Winnerl","sequence":"first","affiliation":[{"name":"Walter Schottky Institut and Physik Department, Technische Universit\u00e4t M\u00fcnchen , Am Coulombwall 4, 85748 Garching, Germany"}]},{"given":"Rui N.","family":"Pereira","sequence":"additional","affiliation":[{"name":"Walter Schottky Institut and Physik Department, Technische Universit\u00e4t M\u00fcnchen , Am Coulombwall 4, 85748 Garching, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0068-3505","authenticated-orcid":false,"given":"Martin","family":"Stutzmann","sequence":"additional","affiliation":[{"name":"Walter Schottky Institut and Physik Department, Technische Universit\u00e4t M\u00fcnchen , Am Coulombwall 4, 85748 Garching, Germany"}]}],"member":"317","published-online":{"date-parts":[[2017,5,25]]},"reference":[{"key":"2023062413135236100_c1","doi-asserted-by":"publisher","first-page":"147","DOI":"10.1016\/S0022-0248(97)00075-4","article-title":"Growth of gallium nitride by hydride vapor-phase epitaxy","volume":"178","year":"1997","journal-title":"J. Cryst. Growth"},{"key":"2023062413135236100_c2","doi-asserted-by":"publisher","first-page":"37","DOI":"10.1016\/S0022-0248(98)00551-X","article-title":"Preparation and properties of free-standing HVPE grown GaN substrates","volume":"194","year":"1998","journal-title":"J. Cryst. Growth"},{"key":"2023062413135236100_c3","doi-asserted-by":"publisher","first-page":"6","DOI":"10.1016\/j.jcrysgro.2004.12.169","article-title":"Reactor and growth process optimization for growth of thick GaN layers on sapphire substrates by HVPE","volume":"277","year":"2005","journal-title":"J. Cryst. Growth"},{"key":"2023062413135236100_c4","doi-asserted-by":"publisher","first-page":"L1705","DOI":"10.1143\/JJAP.30.L1705","article-title":"Gan growth using GaN buffer layer","volume":"30","year":"1991","journal-title":"Jpn. J. Appl. Phys., Part 2"},{"key":"2023062413135236100_c5","doi-asserted-by":"publisher","first-page":"3848","DOI":"10.1063\/1.368564","article-title":"Photoluminescence studies of excitonic transitions in GaN epitaxial layers","volume":"84","year":"1998","journal-title":"J. Appl. Phys."},{"key":"2023062413135236100_c6","doi-asserted-by":"publisher","first-page":"1858","DOI":"10.1063\/1.1311596","article-title":"GaN homoepitaxy by metalorganic chemical-vapor deposition on free-standing GaN substrates","volume":"77","year":"2000","journal-title":"Appl. Phys. Lett."},{"key":"2023062413135236100_c7","doi-asserted-by":"publisher","first-page":"2349","DOI":"10.1116\/1.588858","article-title":"Molecular beam epitaxy growth and properties of GaN, AlxGa1\u2013xN, and AlN on GaN\/SiC substrates","volume":"14","year":"1996","journal-title":"J. Vac. Sci. Technol. B"},{"key":"2023062413135236100_c8","doi-asserted-by":"publisher","first-page":"1855","DOI":"10.1063\/1.1305830","article-title":"Control of GaN surface morphologies using plasma-assisted molecular beam epitaxy","volume":"88","year":"2000","journal-title":"J. Appl. Phys."},{"key":"2023062413135236100_c9","doi-asserted-by":"publisher","first-page":"3709","DOI":"10.1063\/1.1787142","article-title":"Polytype transition of n-face GaN: Mg from wurtzite to zinc-blende","volume":"96","year":"2004","journal-title":"J. Appl. Phys."},{"key":"2023062413135236100_c10","doi-asserted-by":"publisher","first-page":"075316","DOI":"10.1103\/PhysRevB.91.075316","article-title":"Kinetics of optically excited charge carriers at the GaN surface","volume":"91","year":"2015","journal-title":"Phys. Rev. B"},{"key":"2023062413135236100_c11","doi-asserted-by":"publisher","first-page":"304","DOI":"10.1063\/1.357144","article-title":"Analysis of deep levels in n-type GaN by transient capacitance methods","volume":"76","year":"1994","journal-title":"J. Appl. Phys."},{"key":"2023062413135236100_c12","doi-asserted-by":"publisher","first-page":"6443","DOI":"10.1143\/JJAP.33.6443","article-title":"Characterization of the shallow and deep levels in Si doped GaN grown by metal-organic vapor phase epitaxy","volume":"33","year":"1994","journal-title":"Jpn. J. Appl. Phys., Part 1"},{"key":"2023062413135236100_c13","doi-asserted-by":"publisher","first-page":"1721","DOI":"10.1063\/1.115028","article-title":"Effects of column III alkyl sources on deep levels in GaN grown by organometallic vapor phase epitaxy","volume":"67","year":"1995","journal-title":"Appl. Phys. Lett."},{"key":"2023062413135236100_c14","doi-asserted-by":"publisher","first-page":"2525","DOI":"10.1063\/1.117727","article-title":"Deep-level defects and n-type-carrier concentration in nitrogen implanted GaN","volume":"69","year":"1996","journal-title":"Appl. Phys. Lett."},{"key":"2023062413135236100_c15","first-page":"Y5.37","volume-title":"Deep Defects in Fe-Doped GaN Layers Analysed by Electrical and Photoelectrical Spectroscopic Methods","year":"2004"},{"key":"2023062413135236100_c16","doi-asserted-by":"publisher","first-page":"125213","DOI":"10.1103\/PhysRevB.71.125213","article-title":"Characterization of deep defects responsible for the quenching behavior in undoped GaN layers","volume":"71","year":"2005","journal-title":"Phys. Rev. B"},{"key":"2023062413135236100_c17","doi-asserted-by":"publisher","first-page":"463","DOI":"10.1063\/1.112337","article-title":"Deep level defects in n-type GaN","volume":"65","year":"1994","journal-title":"Appl. Phys. Lett."},{"key":"2023062413135236100_c18","doi-asserted-by":"publisher","first-page":"1340","DOI":"10.1063\/1.113235","article-title":"Photoemission capacitance transient spectroscopy of n-type GaN","volume":"66","year":"1995","journal-title":"Appl. Phys. Lett."},{"key":"2023062413135236100_c19","doi-asserted-by":"publisher","first-page":"3775","DOI":"10.1063\/1.116613","article-title":"Thermally stimulated current trap in GaN","volume":"68","year":"1996","journal-title":"Appl. Phys. Lett."},{"key":"2023062413135236100_c20","doi-asserted-by":"publisher","first-page":"2040","DOI":"10.1063\/1.368262","article-title":"Analysis of deep traps in hexagonal molecular beam epitaxy-grown GaN by admittance spectroscopy","volume":"84","year":"1998","journal-title":"J. Appl. Phys."},{"key":"2023062413135236100_c21","doi-asserted-by":"publisher","first-page":"226","DOI":"10.1016\/S0921-5107(98)00371-7","article-title":"Characterization of optical induced defect-band-transitions in MBE grown gallium nitride by optical admittance spectroscopy","volume":"59","year":"1999","journal-title":"Mater. Sci. Eng. B"},{"key":"2023062413135236100_c22","doi-asserted-by":"publisher","first-page":"546","DOI":"10.1063\/1.127039","article-title":"Photoelectric properties of the 0.44 eV deep level-to-band transition in gallium nitride investigated by optical admittance spectroscopy","volume":"77","year":"2000","journal-title":"Appl. Phys. Lett."},{"key":"2023062413135236100_c23","doi-asserted-by":"publisher","first-page":"121308","DOI":"10.1103\/PhysRevB.66.121308","article-title":"Band bending and photoemission-induced surface photovoltages on clean","volume":"66","year":"2002","journal-title":"Phys. Rev. B"},{"key":"2023062413135236100_c24","doi-asserted-by":"publisher","first-page":"111901","DOI":"10.1063\/1.3564892","article-title":"Transient surface photovoltage in n- and p-GaN as probed by x-ray photoelectron spectroscopy","volume":"98","year":"2011","journal-title":"Appl. Phys. Lett."},{"key":"2023062413135236100_c25","doi-asserted-by":"publisher","first-page":"2556","DOI":"10.1063\/1.1774245","article-title":"Transient photovoltage in GaN as measured by atomic force microscope tip","volume":"96","year":"2004","journal-title":"J. Appl. Phys."},{"key":"2023062413135236100_c26","doi-asserted-by":"publisher","first-page":"172111","DOI":"10.1063\/1.3511541","article-title":"Photoassisted Kelvin probe force microscopy at GaN surfaces the role of polarity","volume":"97","year":"2010","journal-title":"Appl. Phys. Lett."},{"key":"2023062413135236100_c27","doi-asserted-by":"publisher","first-page":"051210","DOI":"10.1116\/1.4751276","article-title":"Effects of polarity and surface treatment on Ga- and n-polar bulk GaN","volume":"30","year":"2012","journal-title":"J. Vac. Sci. Technol. B"},{"key":"2023062413135236100_c28","doi-asserted-by":"publisher","first-page":"011206","DOI":"10.1116\/1.4904742","article-title":"Determination of GaN polarity on periodically oriented surfaces","volume":"33","year":"2015","journal-title":"J. Vac. Sci. Technol. B"},{"key":"2023062413135236100_c29","doi-asserted-by":"publisher","first-page":"6770","DOI":"10.1021\/acs.nanolett.5b02607","article-title":"Assessment of polarity in GaN self-assembled nanowires by electrical force microscopy","volume":"15","year":"2015","journal-title":"Nano Lett."},{"key":"2023062413135236100_c30","doi-asserted-by":"publisher","first-page":"9748","DOI":"10.1103\/PhysRevB.59.9748","article-title":"Yellow luminescence and related deep levels in unintentionally doped GaN films","volume":"59","year":"1999","journal-title":"Phys. Rev. B"},{"key":"2023062413135236100_c31","doi-asserted-by":"publisher","first-page":"15573","DOI":"10.1103\/PhysRevB.61.15573","article-title":"Grain-boundary-controlled transport in GaN layers","volume":"61","year":"2000","journal-title":"Phys. Rev. B"},{"key":"2023062413135236100_c32","doi-asserted-by":"publisher","first-page":"390","DOI":"10.1063\/1.1330553","article-title":"Surface states and surface oxide in GaN layers","volume":"89","year":"2001","journal-title":"J. Appl. Phys."},{"key":"2023062413135236100_c33","doi-asserted-by":"publisher","first-page":"162116","DOI":"10.1063\/1.3122934","article-title":"Photoadsorption and photodesorption for GaN","volume":"94","year":"2009","journal-title":"Appl. Phys. Lett."},{"key":"2023062413135236100_c34","doi-asserted-by":"publisher","first-page":"4892","DOI":"10.1016\/j.physb.2009.08.230","article-title":"Role of the surface in the electrical and optical properties of GaN","volume":"404","year":"2009","journal-title":"Physica B"},{"key":"2023062413135236100_c35","doi-asserted-by":"publisher","first-page":"113535","DOI":"10.1063\/1.3430979","article-title":"Surface photovoltage in undoped n-type GaN","volume":"107","year":"2010","journal-title":"J. Appl. Phys."},{"key":"2023062413135236100_c36","doi-asserted-by":"publisher","first-page":"041205","DOI":"10.1116\/1.3605299","article-title":"Comparison of surface photovoltage behavior for n-type versus p-type GaN","volume":"29","year":"2011","journal-title":"J. Vac. Sci. Technol. B"},{"key":"2023062413135236100_c37","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1016\/S0167-5729(99)00002-3","article-title":"Surface photovoltage phenomena: Theory, experiment, and applications","volume":"37","year":"1999","journal-title":"Surf. Sci. Rep."},{"key":"2023062413135236100_c38","doi-asserted-by":"publisher","first-page":"3209","DOI":"10.1063\/1.119157","article-title":"Optical properties of wurtzite structure GaN on sapphire around fundamental absorption edge (0.78\u20134.77 eV) by spectroscopic ellipsometry and the optical transmission method","volume":"70","year":"1997","journal-title":"Appl. Phys. Lett."},{"key":"2023062413135236100_c39","doi-asserted-by":"publisher","first-page":"1190","DOI":"10.1063\/1.362924","article-title":"Study of oxygen chemisorption on the GaN(0001)(1\u2009\u00d7\u20091) surface","volume":"80","year":"1996","journal-title":"J. Appl. Phys."},{"key":"2023062413135236100_c40","volume-title":"Properties of Advanced Semiconductor Materials GaN, AlN, InN, BN, SiC, SiGe","year":"2001"},{"key":"2023062413135236100_c41","doi-asserted-by":"publisher","first-page":"337","DOI":"10.1063\/1.1371941","article-title":"Surface potential measurements on GaN and AlGaN\/GaN heterostructures by scanning Kelvin probe microscopy","volume":"90","year":"2001","journal-title":"J. Appl. Phys."},{"key":"2023062413135236100_c42","first-page":"Y5.39","volume-title":"Band Bending Near the Surface in GaN as Detected by a Charge Sensitive Probe","year":"2004"},{"key":"2023062413135236100_c43","doi-asserted-by":"publisher","first-page":"4249","DOI":"10.1063\/1.367182","article-title":"Gan (0001)- (1\u2009\u00d7\u20091) surfaces composition and electronic properties","volume":"83","year":"1998","journal-title":"J. Appl. Phys."}],"container-title":["Journal of Applied Physics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pubs.aip.org\/aip\/jap\/article-pdf\/doi\/10.1063\/1.4983846\/13862455\/205307_1_online.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/pubs.aip.org\/aip\/jap\/article-pdf\/doi\/10.1063\/1.4983846\/13862455\/205307_1_online.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,6,25]],"date-time":"2023-06-25T01:45:43Z","timestamp":1687657543000},"score":1,"resource":{"primary":{"URL":"https:\/\/pubs.aip.org\/jap\/article\/121\/20\/205307\/153692\/Photo-induced-changes-of-the-surface-band-bending"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,5,25]]},"references-count":43,"journal-issue":{"issue":"20","published-print":{"date-parts":[[2017,5,28]]}},"URL":"https:\/\/doi.org\/10.1063\/1.4983846","relation":{},"ISSN":["0021-8979","1089-7550"],"issn-type":[{"value":"0021-8979","type":"print"},{"value":"1089-7550","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2017,5,28]]},"published":{"date-parts":[[2017,5,25]]},"article-number":"205307"}}