臺灣博碩士論文加值系統

本論文中，探討背面接觸式結構與銅銦鎵硒型太陽能電池，以模擬的方法進行研究，建構模型並嘗試改良其結構。
傳統矽晶太陽能電池的結構一般皆為正面接觸式，改用背電極可使電池入光面的陰影區域減少，光吸收區域增加以達到提高短路電流的功用。再者，因為接面全在背面的緣故，入光面的低接面複合速率可以很容易的達成，因此背電極型太陽能電池有大於20%的高效率。
利用雷射參雜的好處有很多，尤其是可以簡單的做到選擇性重參雜而不需要用到微影技術，另一方面是，它的製程環境是在室溫之下，與傳統熱擴散法比較下來，不會有熱應力影響。雷射參雜目前主要應用在太陽能電池的部分有，形成正面射極與背面場、背電極型太陽能電池、雙面照光式太陽能電池，等等。
銅銦鎵硒型太陽能電池目前已經被廣泛的使用，唯其緩衝程材料多使用硫化鎘，鎘對於環境與人體皆有蠻大的壞處，因此找到了硫化鋅做為替代，論文中探討了緩衝層對於銅銦鎵硒型太陽能電池的影響，以及兩種緩衝層材料的比較。
最後一種結合矽與銅銦鎵硒的新型異質結構太陽能電池為主要的討論對象，

In this thesis, to study interdigitated back contact and CIGS based solar cell, we use TCAD sentaurus to simulate characteristics of solar cell. We build the model and try to improve the structure and get better efficiency.
Mostly, the conventional silicon solar cell has front junction near surface. If we change the structure and made all the contact at the back side, the shadow area can be reduced and the absorbed area increased. Therefore higher short circuit current can be reached. The other advantage of all back contact is that the low surface recombination velocity can be achieved easily. For the above reason, the IBC solar cell has high efficiency (>20%).
There are some advantages of LD solar cell: (1) local selective area for emitter or back side field (BSF) can be formed easily without conventional photolithograph process, (2) the process can be fabricated at room temperature for the reduction of thermal stress in the substrate, (3) the atmosphere condition instead of conventional impurity diffusion method at high temperatures. Since the selective area doping can be formed by LD process, the interdigitated back contact (IBC) solar cell is also can be possibly fabricated by this process.

摘要 II
Abstract III
Contents IV
List of Tables VI
List of Figures VII
Chapter 1 1
1.1 Motivation 1
1.2 Organization 2
Chapter 2 5
Interdigitated Back Contact Solar cell 5
2.1 Introduction 5
2.2 Basic IBC solar cell simulation 6
2.2.1 Simulation structure and parameters 6
2.2.2 IBC solar cell structure design 8
2.3 Lateral carrier transport issue 9
2.3.1 Front surface field (FSF) 9
2.3.2 EQE simulation 15
2.4 IBC with selective heavily doping 17
Reference 19
Chapter 3 20
Laser Doping Solar cell Simulation and IBC-SHJ simulation 20
3.1 Laser doping solar cell 20
3.1.1 Introduction 20
3.1.2 Experimental and simulation result of Laser Doping solar cell 21
3.2 Interdigitated back contact solar cell with silicon hetero-junction (IBC-SHJ) 26
3.2.1 simulation result and discuss 28
References 31
Chapter 4 32
CIGS with alternative buffer layers and novel hetero structure of CIGS solar cell (CIGS on Si) 32
4.1 Introduction 32
4.2 CIGS with alternative buffer layers 36
4.2.1 Introduction 36
4.2.2 Simulation result and discussion 38
4.2.3 Conduction band offset in buffer layer and CIGS interface 43
4.3 Novel hetero structure of CIGS solar cell (CIGS on Si) 47
4.3.1 Introduction 47
4.3.2 Simulation result and discussion 48
Chapter 5 54
Summary and Future Work 54
5.1 Summary 54
5.2 Future work 55

List of Tables
Table 2-1 Performance of with and without back side oxide passivation. 7
Table 2-2 Different emitter coverage fraction. 9
Table 2-3 Different pitch width. 11
Table 2-4 Selective heavily doping. 18
Table 3-1 Performance of conventional IBC and IBC-SHJ 28
Table 3-2 Performance of conventional HIT and IBC-SHJ. 30
Table 4-1 Simulation parameter 37
Table 4-2 CdS and ZnS record efficiency 38
Table 4-3 Performance of CdS and ZnS cells 40
Table 4-4 Performance of conventional CIGS and CIGS on silicon cells 49
Table 4-4 Performance of three CIGS on silicon cells 50






List of Figures
Fig. 2-1 Structure of IBC solar cells 6
Fig. 2-4 Lateral transport. Path (a) through base and Path (b) Through (FSF). 10
Fig. 2-6 Band Diagram of FSF and n-type wafer. 12
Fig. 2-7 Efficiency vs. Front SRV 13
Fig. 2-8 (a) Jsc vs. Front SRV 14
(b) Voc vs. Front SRV 14
(c) F.F. vs. Front SRV 15
Fig. 2-9 (a) EQE vs front SRV(structure with FSF) 16
(b) EQE vs front SRV(structure without FSF) 16
Fig. 2-10 structure of selective heavily doping 17
Fig. 3-1 SIMS data of LD solar cell 22
Fig. 3-2 Structure of LD and conventional multi-silicon solar cell 22
Fig. 3-3 Experimental J-V curves of LD and conventional multi-silicon solar cell 23
Fig. 3-4 Simulation J-V curves of LD and conventional multi-silicon solar cell 23
Fig. 3-5 Simulation J-V curves of LD and conventional multi-silicon solar cell 24
Fig. 3-6 EQE of LD solar cell and conventional multi-silicon solar cell 25
Fig. 3-7 Structure of IBC-SHJ 27
Fig. 3-8 light J-V of conventional IBC and IBC-SHJ 28
Fig. 3-9 Dark current of conventional IBC and IBC-SHJ 29
Fig. 3-10 Light J-V of conventional HIT and IBC-SHJ 30
Fig. 4-1 Band gap of CIGS with different Ga content 33
Fig. 4-2 Schematic energy levels of CBM and VBM in CIGS material. 34
Fig. 4-3 Absorption coefficient of CIGS with different Ga content 35
Fig. 4-4 Absorption coefficient of CIGS with different Ga content 36
Fig. 4-5 illuminated J-V curve of two different buffer layer 39
Fig. 4-6 Dark J-V curve of two different buffer layer 39
Fig. 4-7 (a) Band diagram of buffer layer and CIGS interface. 40
(b) Band diagram of buffer layer and CIGS interface. 41
Fig. 4-8 Band diagram of buffer layer and CIGS interface – same dielectric constant. 42
Fig. 4-9 Dark J-V curve of two different buffer layer – same dielectric constant. 43
Fig. 4-9 CIGS performance vs CBO 44
Fig. 4-10 Simulation result of Jsc vs CBO 45
Fig. 4-11 Band diagram of different CBO 46
Fig. 4-12 Structure of CIGS on silicon 47
Fig. 4-14 Illuminated J-V curve of three CIGS on Silicon solar cells 50

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