CONCEPTUAL COMPARISON BETWEEN LHC SILICON DETECTORS AND SILICON

CONCEPTUAL COMPARISON BETWEEN LHC SILICON DETECTORS AND SILICON SOLAR CELLS Dr. Adnan Ali Department of Physics Government College University Faisalabad

What are Silicon Detectors? A pn junction formed by silicon is the Si detector.

Common applications of Si Detectors • Nuclear Physics • Medical Physics for Imaging • Particle Physics • Crystallography • Astrophysics

Why Silicon? • There are other materials that can be used for detector but due to some limitations they are not used for example Ø Germanium: small bandgap and needs cooling usually ØDiamond: large bandgap, radiation resistant but low signal and high cost Ø other materials from III-V and II-VI group most of these are expensive and/or lack of equipment's required/less experience with industry.

Types of Silicon by Growth Mode • Cz Silicon • Fz-Silicon • Mc-Silicon

Difference Between Si detector and Si Solar Cells • The basic difference between a Silicon detector and a Si solar cells is: • Si Detectors in LHC are reversed biased • Si solar cells operate under forward bias conditions

• Due to reverse biasing of the Si detectors, the reverse leakage current is very crucial parameter in the operation of Si detectors.

Schematic of Si Detector used in LHC

Operation of Si Detector/Solar Cell p-Si n++-Si

ICRES_2014 10 Passivated Emitter Rear Locally Diffused Cell

ICRES_2014 11 IBC Cell Absence of Front Metallization – IBC cell No Optical Shadow losses but electronic Shadow losses – IBC cells

Basic Steps in the fabrication of Silicon Solar Cell

Texturing Results on C-Si (Cz)

Optimization of Back Contacts by TCAD Simulations

ICRES_2014 17 Surface Recombination Velocity for Various Substrates

Jsc response of different emitter Solar Cells

ICRES_2014 Comparison of IBC cells with Standard Cells 19

20 Jsc vs Bulk life time for IBC Cells

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