Photoconductivity and photoluminescence under bias in GaInNAs/GaAs MQW p-i-n structures
© khalil et al.; licensee Springer. 2012
Received: 10 July 2012
Accepted: 12 September 2012
Published: 28 September 2012
The low temperature photoluminescence under bias (PLb) and the photoconductivity (PC) of a p-i-n GaInNAs/GaAs multiple quantum well sample have been investigated. Under optical excitation with photons of energy greater than the GaAs bandgap, PC and PLb results show a number of step-like increases when the sample is reverse biased. The nature of these steps, which depends upon the temperature, exciting wavelength and intensity and the number of quantum wells (QWs) in the device, is explained in terms of thermionic emission and negative charge accumulation due to the low confinement of holes in GaInNAs QWs. At high temperature, thermal escape from the wells becomes much more dominant and the steps smear out.
Dilute nitride research has sparked considerable interest from fundamental physics to industrial applications, and nowadays, several devices based on GaInNAs/GaAs heterostructures are commercially available [1–7]. The interest on this material started from the discovery that adding small amounts of nitrogen to GaAs and GaInAs resulted in a relatively large redshift in bandgap , leading to the realisation of 1.3- and 1.55 μm wavelength devices  with strong electron confinement with the use of the well-established GaAs technology.
Extensive work has been carried out on dilute nitrides, and the demonstration of dilute nitride-based LEDs, lasers [10–12] and solar cell devices  has already been achieved. In a recently published study , we observed several oscillations in the current-voltage (I V) characteristics of p-i-n GaInNAs/GaAs multiple quantum well (MQW) structures at low temperature under illumination. By performing the experiment at different photon wavelengths, it was established that the optical transitions in GaInNAs quantum wells were the origin of these oscillations. In this paper, we further investigate the oscillations by studying at the photoluminescence under bias. These results give a more complete understanding of the underlying mechanisms such as thermal escape, trapping, recombination and charge accumulation.
The structure studied was a Ga0.952In0.048N0.016As0.984/GaAs p-i-n photodiode grown by molecular beam epitaxy (MBE) on an n-doped (100) oriented GaAs substrate. The intrinsic region consists of 10 undoped GaInNAs QWs with varying thickness from 3.8 to 11 nm. The wells were separated from each other by 20 nm thick and from the bulk region by 40 nm intrinsic GaAs barriers. The active region is sandwiched between a 250 nm Be p-doped GaAs layer with doping density of 2 × 1018 cm−3 and a 600 nm Si n-GaAs layer with 5 × 1017 cm−3 doping density. The sample [see Additional file 1 was fabricated in the shape of a mesa-structure, with top circular aperture of 1 mm diameter. Further details about growth and fabrication can be found in our previous publication .
Results and discussion
where is the effective mass for the carriers in the well; Ebarrier is the energy difference between the sub-band and the barrier; and L is the well width.
Photocurrent and integrated photoluminescence measurements on a GaInNAs/GaAs multi-quantum well based p-i-n diode are performed at T = 100 K as a function of applied bias. The analysis reveals that under reverse bias, clear oscillations in the PC and PLb signals are observed. The difference in the thermal escape time of electrons and holes causes the accumulation of negative charge in the wells giving rise to the observed current oscillations.
We would like to thank COST action MP0805 and EPSRC grant EP/P503965/01 grants for their funding. We are also grateful to Tampere University of Technology, Optoelectronics Research Centre, Finland for growing the samples.
- Ellmers C, Hohnsdorf F, Koch J, Agert C, Leu S, Karaiskaj D, Hofmann M, Stolz W, Ruhle WW: Ultrafast (GaIn)(NAs)/GaAs vertical-cavity surface-emitting laser for the 1.3 μm wavelength regime. Appl Phys Lett 1999, 74: 2271. 10.1063/1.123821View ArticleGoogle Scholar
- Choquette KD, Klem JF, Fischer AJ, Blum O, Allerman AA, Fritz IJ, Kurtz SR, Breiland WG, Sieg R, Geib KM, Scott JW, Naone RL: Room temperature continuous wave InGaAsN quantum well vertical-cavity lasers emitting at 1.3 μm. Electron Lett 2000, 36: 1388. 10.1049/el:20000928View ArticleGoogle Scholar
- Heroux JB, Yang X, Wang WI: GaInNAs resonant-cavity-enhanced photodetector operating at 1.3 μm. Appl Phys Lett 1999, 75: 2716. 10.1063/1.125126View ArticleGoogle Scholar
- Kinsey GS, Gotthold DW, Holmes AL, Campbell JC: GaNAs resonant-cavity avalanche photodiode operating at 1.064 μm. Appl Phys Lett 2000, 77: 1543. 10.1063/1.1308272View ArticleGoogle Scholar
- Jalili YS, Stavrinou PN, Roberts JS, Parry G: Electro-absorption and electro-refraction in InGaAsN quantum well structures. Electron Lett 2002, 38: 343. 10.1049/el:20020236View ArticleGoogle Scholar
- Kurtz SR, Allerman AA, Jones ED, Gee JM, Banas JJ, Hammons BE: InGaAsN solar cells with 1.0 eV band gap, lattice matched to GaAs. Appl Phys Lett 1999, 74: 729. 10.1063/1.123105View ArticleGoogle Scholar
- Balcioglu A, Ahrenkiel RK, Friedman DJ: Evidence of an oxygen recombination center in p+–n GaInNAs solar cells. Appl Phys Lett 2000, 76: 2397. 10.1063/1.126383View ArticleGoogle Scholar
- Kondow M, Uomi K, Niwa A, Kitatani T, Watahiki S, Yazawa Y: GaInNAs: a novel material for long-wavelength-range laser diodes with excellent high-temperature performance. J Appl Phys 1996, 35: 1273. 10.1143/JJAP.35.1273View ArticleGoogle Scholar
- Weyers M, Sato M, Ando H: Red shift of photoluminescence and absorption in dilute GaAsN alloy layers. J Appl Phys 1992, 31: 853. 10.1143/JJAP.31.L853View ArticleGoogle Scholar
- Nakamura S: GaN growth using GaN buffer layer. Jpn J Appl Phys 1991, 30: 1705. 10.1143/JJAP.30.1705View ArticleGoogle Scholar
- Nakamura S, Mukai T, Senoh M, Iwasa N: High-dose implantation of MeV carbon ion into silicon. Jpn J Appl Phys 1992, 31: 139. 10.1143/JJAP.31.139View ArticleGoogle Scholar
- Nakamura S, Senoh M, Nagahama S, Iwasa N, Yamada T, Matsushita T, Kiyaku H, Sugimoto Y: InGaN-based multi-quantum-well-structure laser diodes. Jpn J Appl Phys 1996, 35: 74. 10.1143/JJAP.35.L74View ArticleGoogle Scholar
- Kieblich G, Wacker A, Scholl E, Vitusevich SA, Belayev AE, Danylyuk SV, Forster A, Klein N, Henini M: Nonlinear charging effect of quantum dots in a p-i-n diode. Phys Rev B 2003, 68: 125331.View ArticleGoogle Scholar
- Khalil HM, Mazzucato S, Royall B, Balkan N, Puustinen J, Korpijärvi VM, Guina M: Photocurrent oscillations in GaInNAs /GaAs multi-quantum well p-i-n structures. IEEE 2011, 978: 127.Google Scholar
- Royall B, Balkan N, Mazzucato S, Khalil H, Hugues M, Roberts JS: Comparative study of GaAs and GaInNAs/GaAs multi-quantum well solar cells. Phys Status Solidi B 2011, 248: 1191. 10.1002/pssb.201000774View ArticleGoogle Scholar
- Potter RJ, Balkan N: Optical properties of GaInNAs and GaNAs QWs. J Phys Condens Matter 2004, 16: 3387. 10.1088/0953-8984/16/31/026View ArticleGoogle Scholar
- Zhao QX, Wang SM, Wei YQ: Radiative recombination of localized excitons and mobility edge excitons in GaInNAs/GaAs quantum wells with strong carrier localization. Phys Lett A 2005, 341: 297. 10.1016/j.physleta.2005.04.089View ArticleGoogle Scholar
- Mazzucato S, Potter RJ, Erol A, Balkan N, Chalker PR, Joyce TB, Bullough TJ, Marie X, Carrhre H, Bedel E, Lacoste G, Arnoult A, Fontaine C: S-shaped behaviour of the temperature-dependent energy band gap in dilute nitrides. Physica E 2003, 17: 242.View ArticleGoogle Scholar
- Khalil HM, Mazzucato S, Ardali S, Celik O, Mutlu S, Royall B, Tiras E, Balkan N, Puustinen J, Korpijärvi VM, Guina M: Temperature and magnetic field effect on oscillations observed in GaInNAs/GaAs multiple quantum wells structures. Mat Sci and Engin B 2012, 177: 729. 10.1016/j.mseb.2011.12.022View ArticleGoogle Scholar
- Schneider H, Klitzing KV: Thermionic emission and Gaussian transport of holes in a GaAs/AlxGa1-xAs multiple-quantum-well structure. Phys Rev B 1988, 38: 6160. 10.1103/PhysRevB.38.6160View ArticleGoogle Scholar
- Van de Walle CG: Band lineups and deformation potentials in the model-solid theory. Phys Rev B 1871, 1989: 39.Google Scholar
- Capasso F, Mohammed K, Cho AY: Resonant tunneling through double barriers, perpendicular quantum transport phenomena in superlattices, and their device applications. IEEE J Quantum Elect 1853, 1986: 22.Google Scholar
- Smoliner J, Christanell R, Hauser M, Gornik E, Weimann G, Ploog K: Fowler–Nordheim tunneling and conduction-band discontinuity in GaAs/GaAlAs high electron mobility transistor structures. App Phys Lett 1987, 50: 1727. 10.1063/1.97729View ArticleGoogle Scholar
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