Photodetectors on structures with vertically correlated dot clusters

Long photocarrier lifetime is a key issue for improving of room-temperature infrared photodetectors. Detectors based on nanostructures with quantum dot clusters have the strong potential to overcome the limitations in quantum well detectors due to various possibilities for engineering of specific kinetic and transport properties. Here we review photocarrier kinetics in traditional QDIPs and present results of our investigations related to the QD structures with vertically correlated dot clusters (VCDC). Modern technologies allow for fabrication of various VCDC with controllable parameters, such as the cluster size, a distance between clusters, dot occupation etc. Modeling of photocarrier kinetics in VCDC structures shows that the photocarrier capture time exponentially increases with increasing of the number of dots in a cluster. It also exponentially increases as the occupation of a dot increases. At the same time, the capture processes are weakly sensitive to geometrical parameters, such as the cluster size and the distance between clusters. Compared with ordinary quantum-dot structures, where the photoelectron lifetime at room temperatures is of the order of 1-10 ps, the VCDC structures allow for increasing the lifetime up to three orders of magnitude. We also study the nonlinear effects of the electric field and optimize operating regimes of photodetectors. Complex investigations of these structures pave the way for optimal design of the room-temperature QDIPs.

[1]  H. Sakaki,et al.  Multidimensional quantum well laser and temperature dependence of its threshold current , 1982 .

[2]  V. Mitin,et al.  HOT-ELECTRON TRANSPORT IN QUANTUM-DOT PHOTODETECTORS , 2008 .

[3]  A. Karmous,et al.  Ge dot organization on Si substrates patterned by focused ion beam , 2004 .

[4]  Mohamed Henini,et al.  TEMPERATURE DEPENDENCE OF THE OPTICAL PROPERTIES OF INAS/ALYGA1-YAS SELF-ORGANIZED QUANTUM DOTS , 1999 .

[5]  M. Schramboeck,et al.  Nano-patterning and growth of self-assembled quantum dots , 2006, Microelectron. J..

[6]  M. Stroscio,et al.  Quantum-dot photodetector operating at room temperatures: diffusion-limited capture , 2002 .

[7]  G. Bauer,et al.  Structural properties of self-organized semiconductor nanostructures , 2004 .

[8]  G. Strasser,et al.  In-based quantum dots on AlxGa1-xAs surfaces , 2007 .

[9]  John E. Bowers,et al.  1.3 μm photoluminescence from InGaAs quantum dots on GaAs , 1995 .

[10]  P. Klang,et al.  InAs/AlGaAs QDs for intersubband devices , 2008 .

[11]  E. Bertagnolli,et al.  Study of focused ion beam response of GaAs in the nanoscale regime , 2002 .

[12]  K. Cheng,et al.  Site-controlled InAs quantum dots regrown on nonlithographically patterned GaAs , 2005 .

[13]  David T. D. Childs,et al.  1.3 µm Room Temperature Emission from InAs/GaAs Self-Assembled Quantum Dots , 1999 .

[14]  L. Goldstein,et al.  Growth by molecular beam epitaxy and characterization of InAs/GaAs strained‐layer superlattices , 1985 .

[15]  E. Bertagnolli,et al.  Advanced nanoscale material processing with focused ion beams , 2004 .

[16]  Vladimir Mitin,et al.  Quantum dot photodetectors based on structures with collective potential barriers , 2010, OPTO.

[17]  G. Strasser,et al.  Independent control of InAs quantum dot density and size on AlxGa1–xAs surfaces , 2008 .

[18]  G. Bauer,et al.  Site-controlled and size-homogeneous Ge islands on prepatterned Si (001) substrates , 2004 .

[19]  Leonard,et al.  Critical layer thickness for self-assembled InAs islands on GaAs. , 1994, Physical review. B, Condensed matter.

[20]  D. Seliuta,et al.  Modulated reflectance study of InAs quantum dot stacks embedded in GaAs/AlAs superlattice , 2009 .

[21]  James L. Merz,et al.  Visible luminescence from semiconductor quantum dots in large ensembles , 1995 .

[22]  Vladimir Mitin,et al.  High performance of IR detectors due to controllable kinetics in quantum-dot structures , 2008, Optical Engineering + Applications.

[23]  M. Asada,et al.  Gain and the threshold of three-dimensional quantum-box lasers , 1986 .

[24]  G. Kar,et al.  Material distribution across the interface of random and ordered island arrays. , 2004, Physical review letters.

[25]  V. Mitin,et al.  INFRARED QUANTUM-DOT DETECTORS WITH DIFFUSION-LIMITED CAPTURE , 2007 .