EEE23 Low Cost and High Efficiency Si/TMO Heterojunction Solar cell - - PowerPoint PPT Presentation

EEE23

Low Cost and High Efficiency Si/TMO Heterojunction Solar cell

Loh Zhang Chao, Xavier | Lim Hua En Dr Rusli | Dr Ari Bimo Prakoso

1. Rationale behind

• ur research

Why we decided to embark

• n this research

Rationale

○ High Temperature

• during doping of P-

type and N-type Si junctions

3

○ High Costs ○ High Payback Time

• f > 6 years

Traditional Solar Cells

Unfavourable for widespread application

4

Background of our Research

Transition Metal Oxides such as MoO3, V2O5 & Cu2O have shown favourable properties as P-type Si junction replacements ➢ High Work Functions that help form strong electronic barrier with nSi ➢ Lower Temperature of production ➢ Lower Cost that allows greater deployment ➢ More stable than other organic polymer material

“

Research Goal

• To identify which TMO is the best out of the

three to spearhead future research into TMO/nSI Solar Cell research

6

“

Methodology

7

Wafer Cutting Cleaning of Samples Characterisatio n of Solar Cell Shadow Mask

• Silver

Contact

Deposition

• f layers
• Back

Contact

• TMO
• ITO

Fabrication of Sample Compare results

8

Structure of our Solar Cell

Some Equipment Used for Fabrication / Characterisation

Electron Beam Evaporation | Radio Frequency Sputtering | Solar Simulator & Machine Machine Keithley Sourcemeter

Electron Beam Evaporation | Radio Frequency Sputtering | Solar Simulator & Machine Machine Keithley Sourcemeter Deposition of

• Back Contact - TMO
• Silver Contacts with Shadow

Mask Deposition of

• ITO

Obtaining Photovoltaic Parameters to compare between solar cells

Specifics on how we used the equipment

Solar Simulator & Keithley Sourcemeter 2 Probe Method for more realistic results Power intensity set at 100mW/cm2 with fixed Sample Size of 1 cm2 1. 2.

3. Characterisation

• f samples

Values obtained from characterisation and analysis

4 different PV parameters measured

• Short Circuit Current

density (Jsc)

• Open Circuit Voltage

(Voc)

• Fill factor (FF)
• Efficiency (PCE)

Short Circuit Current Density (Jsc)

• Measures current

at 0V

• Dependent on

light absorption

• f solar cell and

carriers generated and collected

Open Circuit Voltage (Voc)

• Measures

voltage at 0A

• Dependent on

saturation current, which depends on recombination

• f carriers

Fill Factor (FF)

• Measures the ratio
• f maximum power

to Isc x Voc

• Allows us to

determine the amount of series, shunt resistance in the cell

Maximum Power

Efficiency (PCE)

• The ratio of output

to input power, calculated through Pmax/Pin

• The main point of

comparison between different solar cells

Results

Data and Analysis

Results Collected

Structure

Jsc/ mA cm-

Voc/V FF/% PCE/% MoO3

27.8 0.570 59.8 9.5

V2O5

26.7 0.568 57.0 8.6

Cu2O

30.1 0.261 37.3 2.9

Without TMO

14.8 0.054 24.3 0.2

19

Analysis - Jsc

• Comparable

values for all 3

Struct ure

Jsc/ mA cm-2 Voc/V FF/% PCE/% MoO3

27.8 0.570 59.8 9.5

V2O5

26.7 0.568 57.0 8.6

Cu2O

30.1 0.261 37.3 2.9

Withou t TMO

14.8 0.054 24.3 0.2

• Cu2O has a slightly

higher Jsc value, which could be due to higher capability in photon carrier generation

Analysis - Voc

• MoO3 has highest

Voc value, suggesting lowest rate of recombination

Struct ure

Jsc/ mA cm-2 Voc/V FF/% PCE/% MoO3

27.8 0.570 59.8 9.5

V2O5

26.7 0.568 57.0 8.6

Cu2O

30.1 0.261 37.3 2.9

Withou t TMO

14.8 0.054 24.3 0.2

• Cu2O’s low Voc

value may be due to higher recombination current in the cell

Analysis - FF

• MoO3 also has a

high FF, which suggests the solar cell has very little series resistance/more shunt resistance

Struct ure

Jsc/ mA cm-2 Voc/V FF/% PCE/% MoO3

27.8 0.570 59.8 9.5

V2O5

26.7 0.568 57.0 8.6

Cu2O

30.1 0.261 37.3 2.9

Withou t TMO

14.8 0.054 24.3 0.2

• Cu2O’s lower FF

could be due to higher series resistance in cell

Analysis - PCE

• MoO3 has the

highest PCE value

• f 9.5%, showing

its potential

Struct ure

Jsc/ mA cm-2 Voc/V FF/% PCE/% MoO3

27.8 0.570 59.8 9.5

V2O5

26.7 0.568 57.0 8.6

Cu2O

30.1 0.261 37.3 2.9

Withou t TMO

14.8 0.054 24.3 0.2

• Cu2O’s lower PCE

value of 2.8% was mainly due to the lower Voc and FF values hindering max power

4. Conclusion

Summary of Analysis and areas for further research

Conclusion

• About 20% reduction in

cost

• MoO3 achieved the best

Voc, FF and PCE values, highlighting its favourable properties for use

• Despite relatively lower

PCE values, MoO3 displays potential for future research and large improvements

Areas for future research

• Vary thickness of ITO

and TMO layers to better optimise solar cell

• Use single wavelength

analysis to better analyse the structure of the solar cell, absorption probabilities at different sections

• Utilise alternative

fabrication methods like spin coating