表面微结构对多晶黑硅太阳电池效率的影响(硕士)(论文26000字)
摘 要
黑硅是一种新型的晶硅材料制备工艺，通过工艺在硅片表面制备出陷光结构，大大降低其反射率，由于其反射率很低，所以在肉眼观察时其表面呈现黑色。本文主要通过以下三个方面，提高黑硅太阳电池的电池性能。
（一）优化制绒工作参数。改变腐蚀液配比、反应时间等关于参数，利用少子寿命、反射率、制绒速率、电池效率、开路电压、短路电流获得最佳工艺参数。结果表明：HF(40％)：HN03(65%)：H2O体积比为3：1:2时其反应速率最高，刻蚀30s时制绒效果最优，电池光电转换效率达18.24%。
（二）在最优制绒参数的基础上，利用NaOH腐蚀液对多晶黑硅纳米孔扩孔处理。当扩孔腐蚀时间为40s时，多晶黑硅太阳电池反射率为8.07%，效率为18.00%，此时的电池效率比常规多晶硅电池效率高2.19%，比未经扩孔工艺处理的多晶太阳电池效率高1.49%。
（三）利用ALD技术沉积Al2O3薄膜对电池表面进行钝化，改变参数为沉底温度和退火温度。ALD沉积温度变化范围为200-500℃，退火温度300-450℃，借助QSSPC少子寿命和方块电阻等测试技术实现沉积层最优质量。结果表明：当沉积温度为300℃，退火温度为450℃时，得到的Al2O3薄膜性能最优。
（四）在PERC电池结构中通过比较 Al2O3和Al2O3/SiOx不同叠层获得最优叠层条件。Al2O3/SiOx时叠层的电池性能最优。，电池的光电转化效率达19.6%，开路电压为660mV，短路电流为39mA/cm2。
本文研究的硅片表面微结构参数、多晶黑硅NaOH扩孔的工艺参数以及叠层钝化参数对于进一步提高黑硅太阳电池性能具有十分重要的工艺参考价值。
[关 键 词]: 表面微结构；黑硅太阳电池；原子层沉积；钝化工艺；沉积叠层工艺
Effect of Surface Microstructure on Efficiency of
Polycrystalline Black Silicon Solar Cells
Abstract
Black silicon is a new type of crystalline silicon material preparation process. Through the process, a light trapping structure is prepared on the surface of the silicon wafer, which greatly reduces the reflectance. Due to its low reflectance, the surface is black when observed with the naked eye. This paper mainly improves the battery performance of black silicon solar cells through the following three aspects.
(1) Optimize the texturing work parameters. Change parameters such as corrosion liquid ratio and reaction time, and use the minority life, reflectivity, texturing rate, cell efficiency, open circuit voltage, and short-circuit current to obtain optimal process parameters. The results show that the reaction rate of HF (40%):HN03(65%):H2O volume ratio is 3:1:2, and the best effect of texturing is 30 seconds. The photoelectric conversion efficiency of the battery is 18.24%.
(2) Based on the optimal texturing parameters, the polycrystalline black silicon nanoholes are bored with NaOH etching solution. When the etching time for hole expansion is 40s, the reflectivity of the polycrystalline silicon black solar cell is 8.07%, the efficiency is 18.00%, and the efficiency of the battery at this time is 2.19% higher than that of the conventional polysilicon battery, which is higher than that of the polycrystalline silicon without the hole expanding process. Solar cell efficiency is 1.49%.
(3) Passivation of the surface of the battery by depositing Al2O3 film using ALD technology, change the parameters to sinking temperature and annealing temperature. ALD deposition temperature range of 200-500 °C, annealing temperature 300-450 °C, with QSSPC minority son life and square resistance test technology to achieve the best quality of the deposition layer. The results show that when the deposition temperature is 300 °C and the annealing temperature is 450 °C, the properties of the Al2O3 thin film are optimal.
(4) Optimum lamination conditions were obtained by comparing Al2O3 and Al2O3/SiOx stacks in PERC cell structures. Al2O3/SiOx laminates the best battery performance. The photoelectric conversion efficiency of the battery reached 19.6%, the open circuit voltage was 660mV, and the short-circuit current was 39mA/cm2.
The microstructural parameters of the silicon surface, the process parameters of polycrystalline silicon black NaOH pore expansion, and the passivation parameters of the stack have important process reference value for further improving the performance of the black silicon solar cell.
[Key words]: surface microstructure; black silicon solar cell; atomic layer deposition; passivation process; deposition lamination process
目 录
1 绪 论 1
1.1研究背景与意义 1
1.2 硅太阳能电池 4
1.2.1太阳能电池的原理 4
1.2.2太阳能电池的种类 5
1.3黑硅及黑硅太阳电池 11
1.3.1黑硅刻蚀方法 12
2 太阳能电池的工作原理及其模型 14
2.1 半导体的基本原理 14
2.1.1 半导体的能带 14
2.1.2 PN结 17
2.2 太阳能电池对光的吸收和反射 19
2.3载流子的分离机理 20
2.3.1 p-n结势垒 21
2.3.2肖特基势垒 22
2.3.3背表面场 23
2.4影响转化效率的因素 23
2.4.1入射光在接受器表面上的反射损失 23
2.4.2吸收时的光损失 23
2.4.3吸收后的能量损失 24
2.4.4电压因子 24
2.4.5复合所造成的损失(Jc产生的少数载流子的收集效率) 24
2.4.6元件内阻所引起的损失 25
3表面微结构对黑硅电池光电性能的影响 26
3.1原硅片制绒 26
3.1.1溶液配比对制绒速度与效率的影响 26
3.1.2制绒时长对效率的影响 29
3.1.3本节使用的表征设备 31
3.2.黑硅表面纳米结构的产生原理 32
3.3实验过程 33
3.3.1 制备黑硅太阳能电池 34
3.3.2 NaOH腐蚀时间对扩孔速度的影响 35
3.5结论 38
4 探索原子气相沉积法沉积AL2O3对电池性能的影响 39
4.1原子气相沉积法基本原理 39
4.1.1. ALD法 39
4.1.2. PECVD法 40
4.1.3. 其他方法 40
4.1.4 ALD--Al2O3氧化膜 40
4.1.5 工业化ALD技术 41
4.2探索ALD--- Al2O3实验最佳方案 42
4.2.1 探索ALD沉积温度对沉积层的影响 42
4.2.2 实验过程及结果分析 44
4.2.3 探索退火温度对沉积层质量的影响 45
4.3 探索沉积温度对沉积层质量的影响 47
4.4在PERC电池结构中比较 Al2O3和Al2O3/SiOx叠层性能 49
4.4.1 实验准备 49
4.4.2结果分析 50
4.5本章小结 53
5 结论与展望 54
5.1 结论 54
5.2展望 56
参考文献 57
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