Review Paper of TMDS for optoelectronics

Review paper

1. 1 Advisor : Prof. Ruei -San Chen Advanced Material Laboratory (AML) Bandiyah Sri Aprillia Photodetector Application Graduate Institute of Applied Science and Technology

2. Outline 2 Introduction Background of study - Solar Cells CZTSSe based Solar cells Critical Issues - CZTSSe Solar cells Motivations Alkali Metal Fluoride Electron-selective Contacts Experimental details Results and discussion Conclusion Future Outlook Advanced Material Laboratory (AML) Graduate Institute of Applied Science and Technology

3. 3 Introduction - Requirement good Photodetector

4. Sensitive at specific Spectrum High responsivities and Quantum Efficiency Good Photocurrent Wide Energy Gap 4 Introduction - Requirement good Photodetector

5. 3 Advanced Material Laboratory (AML)

6. 4 Efficiency (Lab scale) Efficiency (Module) Highest Commercial Module Efficiency 2017 Global Production in 2014* ( GWp ) Energy Payback Time * (years) Silicon Technology Monocrystalline 26.6% 24.3% 21.5% 16.9(35.6%) 4.1 Multicrystalline 21.3% 19.9% 16.2% 26.2(55.2%) 3.1 Thin Film Technology CdTe 22.1% 18.6% 16.4% 1.9(4.0%) 1.0 CIGS 22.6% 17.5% 14.9% 1.7(3.6%) 1.7 a-Si 13.6% 12.3% 9.8% 0.8(1.6%) 2.3 Advanced Material Laboratory (AML) Introduction - Commercial solar cell Thin Film Solar Cell Technology Low cost production Lower energy payback time Extendable to flexible substrate Thin film 9.2% multicrystalline 55.2% monocrystalline 35.6 % Market Share 2014 Khagendra P. Bhandari et.al., Renew.Sust.Energy Rev 47, 133-141 (2015) Martin A. Green et.al., Prog . Photovolt : Res. Appl . 25 , 3.13 (2017) RENEW SUST ENERG REV

7. 5 CIGS solar cell (22.6%) by ZSW Cu, In, Ga, Se ( Chalcopyrites ) Commercialized thin film solar cell promising PV material which demonstrated PCE over 22%. CZTSSe solar cell (12.6%) by IBM Cu, Zn, Sn , S or Se Similar structure to CIGS ( Kesterites ) Unlike CIGS, CZTS is composed of only abundant and non-toxic elements Advanced Material Laboratory (AML) Introduction - CZTSSe Based Solar Cell

8. 8 Advanced Material Laboratory (AML) Stéphane Bourdais et. al., Adv. Energy Mater. 1502276 (2016) Voltage deficit of Kesterite : 0.58V-0.77V Voltage deficit of 0.42 V for CIGS, 0.35 V for CdTe and 0.33 V for c-Si Introduction - Critical Issue in CZTSSe V OC deficit Deep Defects (Disorders) (e.g. Cu Zn - , Zn Cu + , Sn Zn 2+ ) Bandgap fluctuation (Band tailing) (e.g. non-uniform strain, S/Se) Contact Losses Interfacial Losses (e.g. wrong band alignment, secondary phase, un-passivated surface)