Towards ink-jet printed fine line front side metallization of crystalline silicon solar cells

Abstract An ink-jet method for fabrication of fine and smooth front side highly conductive silver lines on crystalline Silicon substrate is described. The fabricated conductive silver lines on different substrates are characterized by means optical microscope, optical profilometers, scanning electron microscope (SEM), and electrical measurements. The coffee-ring effect is controlled by increasing the solid loading of the ink from 20 W% to 40 W% and printing at optimum substrate temperature (90–100 °C) and optimum printing parameters. Smooth printed conductive silver lines, with line thickness ranges from 0.8∼0.9 μm for single pass, are obtained. When increased substrate temperature, a significant reduction of spreading of ink was observed. And conductive silver lines obtained at optimum substrate temperature (90–100 °C), free of periodic wrinkles and line bleeding, are produced. The influence of annealing temperature on line resistance, the morphology and functionality of the printed conductive silver lines is optically and electrically analyzed. To deposit thicker lines multiple passes of ink-jet printing were done on polished single crystalline silicon (sc-Si) and standard alkaline (NaOH) textured n + /p single crystalline silicon (n + /p sc-Si). Moreover, the printed conductive silver lines are characterized optically and electrically. And, promising results in terms of printed line thickness and electrical property are achieved.

[1]  T. Dupont,et al.  Capillary flow as the cause of ring stains from dried liquid drops , 1997, Nature.

[2]  Ho-Young Kim,et al.  Drop impact on microwetting patterned surfaces , 2010 .

[3]  Hyungsun Kim,et al.  Effect of the Thermal Properties of Frits on the Electrical\Properties of Screen-Printed Silicon Solar Cells , 2009 .

[4]  Jooho Moon,et al.  Control of colloidal particle deposit patterns within picoliter droplets ejected by ink-jet printing. , 2006, Langmuir : the ACS journal of surfaces and colloids.

[5]  U. Schubert,et al.  Inkjet printing of well-defined polymer dots and arrays. , 2004, Langmuir : the ACS journal of surfaces and colloids.

[6]  Jinhyung Lee,et al.  Analysis of series resistance of crystalline silicon solar cell with two-layer front metallization based on light-induced plating , 2011 .

[7]  W. Kwapil,et al.  High throughput via-metallization technique for multi-crystalline metal wrap through (MWT) silicon solar cells exceeding 16% efficiency , 2010 .

[8]  U. Schubert,et al.  Inkjet-printed silver tracks : low temperature curing and thermal stability investigation , 2008 .

[9]  Robert A. Street,et al.  Jet printing flexible displays , 2006 .

[10]  Jang Sub Kim,et al.  Direct writing of copper conductive patterns by ink-jet printing , 2007 .

[11]  G. Jabbour,et al.  Inkjet Printing—Process and Its Applications , 2010, Advanced materials.

[12]  A. Ho-baillie,et al.  Forming openings to semiconductor layers of silicon solar cells by inkjet printing , 2008 .

[13]  U. Schubert,et al.  Ink‐jet Printing and Microwave Sintering of Conductive Silver Tracks , 2006 .

[14]  Patrick J. Smith,et al.  Direct ink-jet printing and low temperature conversion of conductive silver patterns , 2006 .

[15]  Martin A. Green,et al.  Beneficial and constraining effects of laser scribing in buried‐contact solar cells , 1997 .

[16]  R. Van Overstraeten,et al.  Low-cost industrial technologies of crystalline silicon solar cells , 1997, Proc. IEEE.

[17]  A. Rohatgi,et al.  High‐efficiency (19%) screen‐printed textured cells on low‐resistivity float‐zone silicon with high sheet‐resistance emitters , 2006 .

[18]  A. Marmur,et al.  Marangoni effects in the spreading of liquid mixtures on a solid , 1987 .

[19]  J. Hoornstra,et al.  Lead free metallisation paste for crystalline silicon solar cells: from model to results , 2005, Conference Record of the Thirty-first IEEE Photovoltaic Specialists Conference, 2005..

[20]  Johan Nijs,et al.  Simple integral screenprinting process for selective emitter polycrystalline silicon solar cells , 1991 .

[21]  D. B. Dam,et al.  Experimental study of the impact of an ink-jet printed droplet on a solid substrate , 2004 .

[22]  V. Subramanian,et al.  An ink-jet-deposited passive component process for RFID , 2004, IEEE Transactions on Electron Devices.

[23]  M. Hörteis,et al.  High‐Temperature Contact Formation on n‐Type Silicon: Basic Reactions and Contact Model for Seed‐Layer Contacts , 2010 .

[24]  Derek B. Ingham,et al.  Laminar boundary layer on an impulsively started rotating sphere , 1979 .

[25]  K. Chou,et al.  Fabrication and sintering effect on the morphologies and conductivity of nano-Ag particle films by the spin coating method , 2005 .

[26]  S. Asher,et al.  Development of screen-printed silicon solar cells with high fill factors on 100 /spl Omega//sq emitters , 2004, IEEE Transactions on Electron Devices.

[27]  Sandra M. Troian,et al.  Using convective flow splitting for the direct printing of fine copper lines , 2000 .

[28]  F. Huster,et al.  Physical understanding of printed thick-film front contacts of crystalline Si solar cells—Review of existing models and recent developments , 2006 .

[29]  Brian Derby,et al.  A Low Curing Temperature Silver Ink for Use in Ink‐Jet Printing and Subsequent Production of Conductive Tracks , 2005 .

[30]  Marco Marengo,et al.  Time evolution of liquid drop impact onto solid, dry surfaces , 2002 .

[31]  Ajeet Rohatgi,et al.  Understanding and Use of IR Belt Furnace for Rapid Thermal Firing of Screen-Printed Contacts to Si Solar Cells , 2010, IEEE Electron Device Letters.

[32]  V. Subramanian,et al.  Inkjet-printed line morphologies and temperature control of the coffee ring effect. , 2008, Langmuir : the ACS journal of surfaces and colloids.

[33]  Sunho Jeong,et al.  Direct writing of silver conductive patterns: Improvement of film morphology and conductance by controlling solvent compositions , 2006 .

[34]  S. Glunz,et al.  Fine line printed and plated contacts on high ohmic emitters enabling 20% cell efficiency , 2009, 2009 34th IEEE Photovoltaic Specialists Conference (PVSC).

[35]  Noemi Rozlosnik,et al.  Formation of crystalline ring patterns on extremely hydrophobic supersmooth substrates : Extension of ring formation paradigms , 2005 .

[36]  X. Zhao,et al.  Immobilizing catalysts on porous materials , 2006 .

[37]  U. Schubert,et al.  Inkjet Printing of Polymers: State of the Art and Future Developments , 2004 .