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Semiconductor Physics, Quantum Electronics & Optoelectronics. 2014. V. 17, N 4. P. 331-335.
Photoconductivity mechanism in structures
with Ge-nanoclusters grown on Si(100) surface 1Taras Shevchenko National University of Kyiv, 64/13, Volodymyrska str., 01601 Kyiv, Ukraine 2O. Chuiko Institute of Surface Chemistry, 17, Generala Naumova str., 03164 Kyiv, Ukraine 3V. Lashkaryov Institute of Semiconductor Physics, NAS of Ukraine, 03028 Kyiv, Ukraine Abstract. Interband optical transitions in the epitaxial Si/Ge heterostructures with Ge nanoislands grown on Si(100) surface were investigated using photocurrent spectroscopy. The mechanism of photoconductivity was discussed. It was shown that electron transitions from the ground state of the valence band in a quantum dot to the conduction band of Si surrounding make the main contribution into monopolar photoconductivity below the fundamental absorption edge of crystalline Si. Photoexcited holes were found to be localized in Ge nanoislands inducing the lateral conductivity changes in the near-surface depletion layer of p-Si substrate due to the field-effect. Keywords:Ge-nanocluster, photoconductivity, surface potential, quantum dots. Manuscript received 00.00.14; revised version received 00.00.14; accepted for publication 00.00.14; published online 00.00.14.
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