Passive and Enhanced Grain Boundaries in Solar Cells by Gas Immersion Laser Diffusion

1981 ◽  
Vol 5 ◽  
Author(s):  
G. B. Turner ◽  
D. Tarrant ◽  
D. Aldrich ◽  
R. Pressley ◽  
R. Press
Keyword(s):  
Heat Treatment ◽  
Solar Cells ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Polycrystalline Silicon ◽  
Pulsed Laser ◽  
New Method ◽  
Current Collection ◽  
Liquid Diffusion ◽  
Epitaxial Regrowth

ABSTRACTA new method for making p-n junctions based on immersion in a transparent dopant gas followed by irradiation with a pulsed laser is presented. The surface of the wafer melts, dopant from the gas dissolves in it, and is distributed by liquid diffusion before epitaxial regrowth. This technique, termed GILD for Gas Immersion Laser Diffusion, was used to make solar cells in both monocrystalline and polycrystalline silicon.Laser photocurrent scanning shows that grain boundary recombination is reduced or eliminated in cells made by the GILD technique and current collection is enhanced at some grain boundaries. Heat treatment at 850 ° C prior to GILD causes the same grain boundaries to be recombination active as they are in ordinary diffused cells.

The Effect of Heat Treatment on Grain Boundary Properties in Cast Polycrystalline Silicon

1981 ◽  
Vol 5 ◽  
Author(s):  
P.E. Russell ◽  
C.R. Herrington ◽  
D.E. Burke ◽  
P.H. Holloway
Keyword(s):  
Heat Treatment ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Polycrystalline Silicon ◽  
Surface Recombination ◽  
Device Fabrication ◽  
Solar Cell Device ◽  
Device Structure ◽  
Heat Treated ◽  
Boundary Properties

ABSTRACTThe effects of heat treatment at temperatures appropriate for solar cell device fabrication on grain boundaries in cast poicrystalline silicon have been studied. An MIS device structure using a 200° C heating was used for fabricating test devices on heat treated samples for EBIC studies. Grain boundary effective surface recombination velocities (Seffgb ) and effective mid-grain diffusion lengths were measured. Seffgb was found to increase after heat treatment. Segregation of oxygen to grain boundaries has been observed in heat treated samples.

Imaging Electron Transport across Grain Boundaries in an Integrated Electron and Atomic Force Microscopy Platform: Application to Polycrystalline Silicon Solar Cells

2009 ◽  
Vol 1153 ◽  
Author(s):  
Manuel J Romero ◽  
Fude Liu ◽  
Oliver Kunz ◽  
Johnson Wong ◽  
Chun-Sheng Jiang ◽  
...  
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Solar Cells ◽  
Electron Transport ◽  
Grain Boundaries ◽  
Polycrystalline Silicon ◽  
High Energy ◽  
Dominant Factor ◽  
Force Microscopy ◽  
Atomic Force

AbstractWe have investigated the local electron transport in polycrystalline silicon (pc-Si) thin-films by atomic force microscopy (AFM)-based measurements of the electron-beam-induced current (EBIC). EVA solar cells are produced at UNSW by <i>EVAporation</i> of a-Si and subsequent <i>solid-phase crystallization</i>–a potentially cost-effective approach to the production of pc-Si photovoltaics. A fundamental understanding of the electron transport in these pc-Si thin films is of prime importance to address the factors limiting the efficiency of EVA solar cells. EBIC measurements performed in combination with an AFM integrated inside an electron microscope can resolve the electron transport across individual grain boundaries. AFM-EBIC reveals that most grain boundaries present a high energy barrier to the transport of electrons for both p-type and n-type EVA thin-films. Furthermore, for p-type EVA pc-Si, in contrast with n-type, charged grain boundaries are seen. Recombination at grain boundaries seems to be the dominant factor limiting the efficiency of these pc-Si solar cells.

Self-assembled propylammonium cations at grain boundaries and the film surface to improve the efficiency and stability of perovskite solar cells

2019 ◽  
Vol 7 (41) ◽  
pp. 23739-23746 ◽  
Author(s):  
Chengbin Fei ◽  
Meng Zhou ◽  
Jonathan Ogle ◽  
Detlef-M. Smilgies ◽  
Luisa Whittaker-Brooks ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Perovskite Solar Cells ◽  
Film Surface ◽  
Solar Cell Efficiency ◽  
Cell Efficiency ◽  
Large Size ◽  
Moisture Stability

Large size cation (PA) was introduced into the grain boundary and film surface of the 3D perovskite to improve the solar cell efficiency and moisture stability.

Can Grain Boundaries Improve the Performance of Cu(In,Ga)Se2 Solar Cells?

2007 ◽  
Vol 1012 ◽  
Author(s):  
Uwe Rau ◽  
Uwe Rau
Keyword(s):  
Solar Cells ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
High Performance ◽  
Band Offset ◽  
Device Performance ◽  
Localized Defects ◽  
Recombination Centers ◽  
Numerical Device ◽  
Large Charge

AbstractTwo-dimensional numerical device simulations investigate the influence of grain boundaries on the performance of Cu(In,Ga)Se2 solar cells focussing on the question whether or not grain boundaries can improve the efficiency of those devices. The results unveil the following statements: (i) The mere introduction of a grain boundary by adding localized defects into a device that has a high performance from the beginning is not beneficial. (ii) Polycrystalline solar cells can outperform monocrystalline ones, if the total number of defects is equal in both devices. I.e. a given number of recombination centers is better dealt with if these defects are concentrated at the grain boundary rather than homogeneously distributed in the bulk. (iii) A significant improvement of carrier collection via the grain boundaries is found if the bulk of the devices is assumed as relatively poor. In this situation, addition of defects that are not much recombination ac-tive but provide a large charge density at the grain boundaries can improve the device performance. (iv) Passivation of grain boundaries by an internal band offset in the valence band is effective only if the internal barrier amounts at least to 300 meV.

Atomic Scale Characterisation of Electrodeposited Nanocrystalline Ni-P Alloys

1999 ◽  
Vol 581 ◽  
Author(s):  
Matthias Abraham ◽  
Mattias Thuvandert ◽  
Helen M. Lane ◽  
Alfred Cerezo ◽  
George D.W. Smith
Keyword(s):  
Heat Treatment ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Three Dimensional ◽  
Boundary Segregation ◽  
Atom Probe ◽  
Atomic Scale ◽  
Grain Boundary Segregation ◽  
P Concentration

ABSTRACTNanocrystalline Ni-P alloys produced by electrodeposition have been characterised by three-dimensional atom probe (3DAP) analysis. In the as-deposited materials, there are indications of some variation in P concentration between grains and segregation to grain boundaries. After heat treatment however, strong grain boundary segregation and the formation of Ni3P precipitates have been observed.

Advantages of MIS Processing on Passivated Polycrystalline Silicon

1981 ◽  
Vol 5 ◽  
Author(s):  
G. Rajeswaran ◽  
M. Thayer ◽  
V. J. Rao ◽  
W. A. Anderson
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Polycrystalline Silicon ◽  
Hydrogen Plasma ◽  
Mis Structures

ABSTRACTWacker polycrystalline silicon shows enhanced grain boundary activity after a high temperature (950° C) anneal. It is possible to passivate this effect in a hydrogen plasma. The low temperature (600° C) processing of MIS technology does not activate grain boundaries or deteriorate a passivated specimen. Activated grain boundaries with MIS structures can be used to assess the character of recombination currents. It is concluded that MIS processing is advantageous for passivated polycrystalline silicon.

Precipitation of Copper and Cobalt at Grain Boundaries in Silicon

1989 ◽  
Vol 163 ◽  
Author(s):  
U. Jendrich ◽  
H. J. Möller
Keyword(s):  
Particle Size ◽  
Mössbauer Spectroscopy ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Cooling Rate ◽  
Polycrystalline Silicon ◽  
Mossbauer Spectroscopy ◽  
Low Energy ◽  
Surface Source ◽  
Mößbauer Spectroscopy

AbstractThe precipitation of copper and (radioactive) cobalt at low energy grain boundaries in polycrystalline silicon and bicrystals is investigated. The metals are diffused in from a surface source between 800 - 1000 °C and the precipitation after cooling down is studied by TEM (for Cu) and Mößbauer spectroscopy (for Co). The precipitates are metal suicides. For copper it is shown that they appear in form of colonies containing hundreds of precipitates with a particle size between 5-60 nm. In the grain boundary they nucleate preferentially at dislocations and steps. The distribution and size of the precipitates depend on the cooling rate after the diffusion. In the vicinity of the grain boundary the volume is depleted from the impurities.

Sign in / Sign up

Export Citation Format

Share Document