Work function and induced band bending characterization for engineering of selective contact for solar cells

Marshall Wilson1*, Alexandre Savtchouk1, Ziv Hameiri2, Jie Cui3 and Jacek Lagowski1

1Semilab SDI, Tampa, FL 33617, USA

2University of New South Wales (UNSW), Sydney NSW 2052, Australia

3Australian National University (ANU), Canberra ACT 0200, Australia

Adv. Mater. Lett., 2018, 9 (9), pp 629-631

DOI: 10.5185/amlett.2018.2084

Publication Date (Web): Jun 14, 2018



This work demonstrates the effectiveness of non-contact Kelvin-probe and surface photovoltage characterization of the work function (WF) induced barriers formed in silicon (Si) by thin 5nm carrier selective contact films of MoOx, TiO2 and MgF2.  The calibrated Kelvin probe in the dark and under strong illumination where used to determine the dark WF of the deposited films and the band bending in the Si, FBB = WFDark – WFLight.  The ac-surface photo voltage provided an independent measurement of the Si depletion layer width.  Whole wafer mapping of all parameters can be performed.  For n-type Si the high work function oxides MoOx (WF~5.7eV) and TiO2 (WF~5.0eV) are found to induce a depletion barrier with the height increasing with WF as FBB[eV] = 0.23WF – 0.77, i.e. quite similar to the well-known relationship for metal-silicon contacts.  For the low work function MgF2 film, a depletion barrier was induced only in p-type Si.  For this case, full wafer mapping revealed a lower WF pattern coinciding with larger band bending giving the slope, DFBB/DWF ~ -0.52.  The slopes of 0.23 and 0.52 for n- and p-type Si deviates significantly from the ideal slope of 1.  This result implies that the barrier formation at the Film-Si heterojunction is limited by the effect of interfacial layers and interface states in analogy to the well-known effects in Metal-Si contacts. It is believed that this demonstrated very fast, preparation-free, non-contact characterization technique can benefit research and engineering of selective contacts for solar cells. 


Solar cell, work function, band bending, hole selective contacts, electron selective contacts.

Current Issue
The Journey of a Decade to Advancing Materials
Are the Electrospun Polymers Polymeric Fibers?
Mechanical and Thermal Properties of Composite Material and Insulation for a Single Walled Tank for Cryogenic Liquids
Prediction of Long-Term Behavior for Dynamically Loaded TPU
Investigation of Doped Titanium Dioxide in Anatase Phase. Study ab initio using Density Functional Theory
Comparison between Single Al2O3 or HfO2 Single Dielectric Layers and their Nanolaminated Systems
Preparation of Stable and Optimized Antibody-gold Nanoparticle Conjugates for Point of Care Test Immunoassays
Resonance-Based Temperature Sensors using a Wafer Level Vacuum Packaged SOI MEMS Process
Integrated System Based on the Hall Sensors Incorporating Compensation of the Distortions
The Efficacy of Cinnamomum Tamala as a Potential Antimicrobial Substance against the Multi-Drug Resistant Enterococcus Faecalis from Clinical Isolates
The Effect of Complexing Reagent on Structural, Electrical and Optical Properties of CuS Thin Film
Laser Cladding of Fluorapatite Nanopowders on Ti6Al4V
Preparation and Evaluation of Sulfonate Polyethylene Glycol Borate Ester as a Modifier of Functional Properties of Complex Petroleum Lithium Grease

Upcoming Congress

Knowledge Experience at Sea TM