Chapter 1 Introduction
1.1 Solar energy
1.2 Solar cell operation
1.2.1 Photovohaic effect
1.2.2 Band discontinuity at heterojunction interface
1.3 Photovoltaic material research
1.4 Background and survey of literature of Cu2ZnSnS4-based solar cells
1.4.1 Properties of Cu2ZnSnS4 thin films
1.4.2 CdS/CZTS heterointerfaces
1.4.3 ZnO/CZTS heterointerface
1.4.4 Secondary phases in kesterite Cu2ZnSnS4 absorber thin film
1.5 First-principles calculation
1.5.1 Density functional theory (DFT)
1.5.2 Exchange-Correlation functional approximations
1.5.3 Pseudopotential
1.6 Objective of this work
1.7 Preview of the monograph
References
Chapter 2 Prediction of the Band Offsets at the CdS/Cu2ZnSnS4 Interface Based on the First-Principles Calculation
2.1 Introduction
2.2 Calculation
2.2.1 Structure of CdS/CZTS heterojunction
2.2.2 Calculation of density of states
2.3 Results and discussion
2.3.1 Calculation of energy levels and predicted VBM positions for the respective layer of atom in the CdS/Cu2ZnSnS4 supercell
2.3.2 Band alignment at the CdS/Cu2ZnSnS4 heterointerface
2.3.3 Charge of each atom for the respective layers in the supercell
2.4 Conclusion
References
Chapter 3 Influences of Crystal Structure and Orientation on Band Offsets at the CdS/Cu2ZnSnS4 Interface
3.1 Introduction
3.2 Calculation
3.2.1 Structure of CdS/CZTS heterojunetion
3.2.2 Calculation of density of states
3.3 Results and discussion
3.3.1 Energies of the reference core levels and VBM for the respective layer
3.3.2 Charge of each atom
3.3.3 Band alignment at the CdS/Cu2ZnSnS4 heterointerfaee
3.4 Conclusion
References
Chapter 4 Band Offsets at the ZnO/Cu2ZnSnS4 Interface Based on the First Principles Calculation
4.1 Introduction
4.2 Calculation
4.2.1 ZnO/CZTS heterostructure
4.2.2 Density of states
4.3 Results and discussion
4.3.1 Effects of interface atomic structure
4.3.2 Effects of strain and the conduction band offset
4.3.3 Consequences with the solar cell properties
4.4 Conclusions
Referanees
Chapter 5 Influence of Secondary Phases in Kesterite-Cu2ZnSnS4 Absorber Material
5.1 Introduction
5.2 Calculation
5.2.1 Crystal structure of CH2SnS3
5.2.2 Density of state
5.3 Result and discussion
5.4 Conclusion
References
Chapter 6 Band Offsets Engineering at CdxZn1-xS/Cu2ZnSnS4 Heterointerface
6.1 Introduction
6.2 Calculation
6.3 Results and discussions
6.3.1 Electronic structures and band gap
6.3.2 Band alignment for Cd1-xZnxS/CZTS heterointerfaces
6.4 Conclusion
References
Chapter 7 Study of Band Offset at ZnS/CueZnIVS4 (IV = Si, Ge, Sn) Heterointerfaces
7.1 Introduction
7.2 Calculation
7.3 Result and discussion
7.3.1 First principles calculation
7.3.2 Numerical simulation
7.4 Conclusion
References
Chapter 8 Conclusions
8.1 Main conclusion of this monograph
8.2 Suggestions for future work
Publications

世界能源的日益紧缺和人们环保意识增强的当下，薄膜太阳能电池应用研究已成为世界各国研究的热点。化合物半导体Cu2ZnSnS4（CZTS）由于持有太阳能电池所要求的最佳禁带宽度和较大的光吸收系数而被广泛研究。本专著内容分为八章，第一章叙述太阳能电池工作原理、CZTS太阳能电池研究背景以及第一性原理计算方法。第二、三、四章利用第一性原理计算方法分别计算了CdS/ CZTS和ZnO/ CZTS异质结界面能带带阶。第五章分析了二次相对CZTS吸收层材料内的影响。第六章调整了Cd1-xZnxS/CZTS异质界面能带结构。第七章以IV 族的Si和Ge代替Sn原子，计算并比较了ZnS/Cu2ZnIVS4（IV=Si,Ge,Sn）界面能带带阶。第八章本专著总结。