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Metal nanoparticle-enhanced photocurrent in GaAs photovoltaic structures with microtextured interfaces.

Dmitruk NL, Borkovskaya OY, Mamontova IB, Mamykin SV, Malynych SZ, Romanyuk VR - Nanoscale Res Lett (2015)

Bottom Line: Three nanoparticle deposition methods have been checked: 1) photoinduced chemical deposition of Au from aqueous AuCl3 solution forming nanowires on the ridges of quasigrating-type surface microrelief, 2) deposition of Ag nanoparticles from colloidal suspension on the GaAs substrate covered with poly(vinylpyridine), and 3) drop and dry deposition of Au/SiO2 core-shell nanoparticles from aqueous colloid solution.The comprehensive investigation of optical reflectance, photoelectric, and electrical characteristics of the fabricated barrier structures has shown the highest photovoltaic parameters for surface microrelief of quasigrating-type and electroless Au nanoparticle deposition.The analysis of characteristics obtained allowed us also to define the mechanisms of the total photocurrent enhancement.

View Article: PubMed Central - PubMed

Affiliation: Department of Polaritonic Optoelectronics, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine, 41 Nauky av., Kyiv, 03028 Ukraine.

ABSTRACT
The photocurrent enhancement effect caused by Au and Ag nanoparticles for GaAs-based photovoltaic structures of surface barrier or p-n junction type with microtextured interfaces has been investigated in dependence on the conditions of nanoparticles deposition and, respectively, on the shape and local dielectric environment of obtained nanoparticle arrays. Three nanoparticle deposition methods have been checked: 1) photoinduced chemical deposition of Au from aqueous AuCl3 solution forming nanowires on the ridges of quasigrating-type surface microrelief, 2) deposition of Ag nanoparticles from colloidal suspension on the GaAs substrate covered with poly(vinylpyridine), and 3) drop and dry deposition of Au/SiO2 core-shell nanoparticles from aqueous colloid solution. The comprehensive investigation of optical reflectance, photoelectric, and electrical characteristics of the fabricated barrier structures has shown the highest photovoltaic parameters for surface microrelief of quasigrating-type and electroless Au nanoparticle deposition. The analysis of characteristics obtained allowed us also to define the mechanisms of the total photocurrent enhancement.

No MeSH data available.


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Surface microreliefs of quasigrating and dendrite-type topologies. AFM images (a,c) and section analysis (b,d) of GaAs surfaces with microrelief of quasigrating (a,b) and dendrite-like type (c,d) investigated by AFM technique (Dimension 3000 system with NanoScope IIIA controller, Digital Instruments, Indianapolis, IN, USA) in the tapping mode with a Si3N4 tip.
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Fig1: Surface microreliefs of quasigrating and dendrite-type topologies. AFM images (a,c) and section analysis (b,d) of GaAs surfaces with microrelief of quasigrating (a,b) and dendrite-like type (c,d) investigated by AFM technique (Dimension 3000 system with NanoScope IIIA controller, Digital Instruments, Indianapolis, IN, USA) in the tapping mode with a Si3N4 tip.

Mentions: Investigated structures have been manufactured on the n-GaAs (100) wafers doped to 1016 to 1017 cm−3 with Te. Surface microreliefs of quasigrating and dendrite-type topologies (Figure 1a,b,c,d) were prepared by wet chemical anisotropic etching in 2HF:2H2SO4:1H2O2 and concentrated HNO3, respectively [7]. Varying the etching conditions (etchant temperature and process duration) allowed us to change both the microrelief depth and mean period of quasigratings. These peculiarities of microrelief are seen in the presented examples of section analysis (Figure 1b,d), and their parameters can be determined by averaging Fourier transformations of AFM data for all cross-sections of AFM image. Three methods of metal nanoparticles deposition were used: 1) photoinduced chemical deposition of Au from aqueous salt AuCl3 solution forming nanoparticles of various shape and size located predominantly at the tops of microrelief and, in particular, in the shape of nanowires on the ridges of quasigrating-type surface microrelief [4], 2) deposition of ca. 100 nm Ag NP from colloidal water suspension on poly(vinylpyridine) (PVP) modified the GaAs substrate (for immobilization of NP) with formation of separated NP and aggregates of NP on dielectric PVP interlayer [9], and 3) drop-coating deposition from aqua colloid solution of Au NP of 15 nm core size covered by silica shell with approximately 20-nm thickness [10]. The first two methods were used for the modification of n-GaAs surface in Au/GaAs surface-barrier structures when a barrier Au layer formed an ohmic contact with metal nanoparticles. In the last method, the SiO2 shell of Au/SiO2 core-shell nanoparticles isolated Au nanoparticles from both a semiconductor and metal contact layer. So, it was used in the case of p-n-GaAs structures with metal electrode forming ohmic contact to p-GaAs layer. Au/GaAs surface-barrier structures were fabricated by thermal evaporation of semitransparent Au layer through the mask with opening of circular or contact grid form. p-n-GaAs junctions were fabricated by low-temperature (550°C) diffusion of Zn in sealed quartz ampoules with following formation of Au:Zn and Au:Ge ohmic contacts to p- and n-GaAs layers [8]. The schematic diagrams of structures under the study are shown in Figure 2a,b,c.Figure 1


Metal nanoparticle-enhanced photocurrent in GaAs photovoltaic structures with microtextured interfaces.

Dmitruk NL, Borkovskaya OY, Mamontova IB, Mamykin SV, Malynych SZ, Romanyuk VR - Nanoscale Res Lett (2015)

Surface microreliefs of quasigrating and dendrite-type topologies. AFM images (a,c) and section analysis (b,d) of GaAs surfaces with microrelief of quasigrating (a,b) and dendrite-like type (c,d) investigated by AFM technique (Dimension 3000 system with NanoScope IIIA controller, Digital Instruments, Indianapolis, IN, USA) in the tapping mode with a Si3N4 tip.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4385134&req=5

Fig1: Surface microreliefs of quasigrating and dendrite-type topologies. AFM images (a,c) and section analysis (b,d) of GaAs surfaces with microrelief of quasigrating (a,b) and dendrite-like type (c,d) investigated by AFM technique (Dimension 3000 system with NanoScope IIIA controller, Digital Instruments, Indianapolis, IN, USA) in the tapping mode with a Si3N4 tip.
Mentions: Investigated structures have been manufactured on the n-GaAs (100) wafers doped to 1016 to 1017 cm−3 with Te. Surface microreliefs of quasigrating and dendrite-type topologies (Figure 1a,b,c,d) were prepared by wet chemical anisotropic etching in 2HF:2H2SO4:1H2O2 and concentrated HNO3, respectively [7]. Varying the etching conditions (etchant temperature and process duration) allowed us to change both the microrelief depth and mean period of quasigratings. These peculiarities of microrelief are seen in the presented examples of section analysis (Figure 1b,d), and their parameters can be determined by averaging Fourier transformations of AFM data for all cross-sections of AFM image. Three methods of metal nanoparticles deposition were used: 1) photoinduced chemical deposition of Au from aqueous salt AuCl3 solution forming nanoparticles of various shape and size located predominantly at the tops of microrelief and, in particular, in the shape of nanowires on the ridges of quasigrating-type surface microrelief [4], 2) deposition of ca. 100 nm Ag NP from colloidal water suspension on poly(vinylpyridine) (PVP) modified the GaAs substrate (for immobilization of NP) with formation of separated NP and aggregates of NP on dielectric PVP interlayer [9], and 3) drop-coating deposition from aqua colloid solution of Au NP of 15 nm core size covered by silica shell with approximately 20-nm thickness [10]. The first two methods were used for the modification of n-GaAs surface in Au/GaAs surface-barrier structures when a barrier Au layer formed an ohmic contact with metal nanoparticles. In the last method, the SiO2 shell of Au/SiO2 core-shell nanoparticles isolated Au nanoparticles from both a semiconductor and metal contact layer. So, it was used in the case of p-n-GaAs structures with metal electrode forming ohmic contact to p-GaAs layer. Au/GaAs surface-barrier structures were fabricated by thermal evaporation of semitransparent Au layer through the mask with opening of circular or contact grid form. p-n-GaAs junctions were fabricated by low-temperature (550°C) diffusion of Zn in sealed quartz ampoules with following formation of Au:Zn and Au:Ge ohmic contacts to p- and n-GaAs layers [8]. The schematic diagrams of structures under the study are shown in Figure 2a,b,c.Figure 1

Bottom Line: Three nanoparticle deposition methods have been checked: 1) photoinduced chemical deposition of Au from aqueous AuCl3 solution forming nanowires on the ridges of quasigrating-type surface microrelief, 2) deposition of Ag nanoparticles from colloidal suspension on the GaAs substrate covered with poly(vinylpyridine), and 3) drop and dry deposition of Au/SiO2 core-shell nanoparticles from aqueous colloid solution.The comprehensive investigation of optical reflectance, photoelectric, and electrical characteristics of the fabricated barrier structures has shown the highest photovoltaic parameters for surface microrelief of quasigrating-type and electroless Au nanoparticle deposition.The analysis of characteristics obtained allowed us also to define the mechanisms of the total photocurrent enhancement.

View Article: PubMed Central - PubMed

Affiliation: Department of Polaritonic Optoelectronics, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine, 41 Nauky av., Kyiv, 03028 Ukraine.

ABSTRACT
The photocurrent enhancement effect caused by Au and Ag nanoparticles for GaAs-based photovoltaic structures of surface barrier or p-n junction type with microtextured interfaces has been investigated in dependence on the conditions of nanoparticles deposition and, respectively, on the shape and local dielectric environment of obtained nanoparticle arrays. Three nanoparticle deposition methods have been checked: 1) photoinduced chemical deposition of Au from aqueous AuCl3 solution forming nanowires on the ridges of quasigrating-type surface microrelief, 2) deposition of Ag nanoparticles from colloidal suspension on the GaAs substrate covered with poly(vinylpyridine), and 3) drop and dry deposition of Au/SiO2 core-shell nanoparticles from aqueous colloid solution. The comprehensive investigation of optical reflectance, photoelectric, and electrical characteristics of the fabricated barrier structures has shown the highest photovoltaic parameters for surface microrelief of quasigrating-type and electroless Au nanoparticle deposition. The analysis of characteristics obtained allowed us also to define the mechanisms of the total photocurrent enhancement.

No MeSH data available.


Related in: MedlinePlus