太阳能的应用是解决能源与环境问题的有效途径,而高转换效率低成本,易于产业化的高效电池技术是太阳电池发展的目标。近年来高转换效率技术层出不穷,例如SE电池(Selective emitter Cell),MWT电池(Metal warp through cell)和EWT电池(Emi...太阳能的应用是解决能源与环境问题的有效途径,而高转换效率低成本,易于产业化的高效电池技术是太阳电池发展的目标。近年来高转换效率技术层出不穷,例如SE电池(Selective emitter Cell),MWT电池(Metal warp through cell)和EWT电池(Emitter Warp through cell)等。这些高效电池均采用了良好的钝化技术。而常规晶硅太阳电池由于没有采用背场钝化技术,只使用铝背场,而经过烧结形成的铝硅合金背表面在减少复合和背反射效果方面有很大的局限性,并且铝硅合金区本身即高复合区,限制了电池效率的进一步提高。因此为了进一步提高开路电压及短路电流,对硅基背表面进行钝化是很有必要的。通过试验,着重比较了SiNx背场钝化层和SiO2背场钝化层对电池电性参数的影响和变化趋势。通过对电池片IQE分析发现,在使用了SiO2或SiNx背场钝化层后,长波区域的IQE响应相比正常电池片有明显提升,说明SiO2或SiNx确实起到钝化作用。而再对电性参数分析后发现,SiO2与SiNx相比可以有效提高电池的Rsh,降低反向电流。同时在EFF测试方面,SiO2与SiNx相比,也具有一定的优势。展开更多
Based on the surface passivation of n-type silicon in a silicon drift detector(SDD), we propose a new passivation structure of SiO2/Al2O3/SiO2 passivation stacks. Since the SiO2 formed by the nitric-acid-oxidation-of-...Based on the surface passivation of n-type silicon in a silicon drift detector(SDD), we propose a new passivation structure of SiO2/Al2O3/SiO2 passivation stacks. Since the SiO2 formed by the nitric-acid-oxidation-of-silicon(NAOS)method has good compactness and simple process, the first layer film is formed by the NAOS method. The Al2O3 film is also introduced into the passivation stacks owing to exceptional advantages such as good interface characteristic and simple process. In addition, for requirements of thickness and deposition temperature, the third layer of the SiO2 film is deposited by plasma enhanced chemical vapor deposition(PECVD). The deposition of the SiO2 film by PECVD is a low-temperature process and has a high deposition rate, which causes little damage to the device and makes the SiO2 film very suitable for serving as the third passivation layer. The passivation approach of stacks can saturate dangling bonds at the interface between stacks and the silicon substrate, and provide positive charge to optimize the field passivation of the n-type substrate.The passivation method ultimately achieves a good combination of chemical and field passivations. Experimental results show that with the passivation structure of SiO2/Al2O3/SiO2, the final minority carrier lifetime reaches 5223 μs at injection of 5×10^(15) cm^(-3). When it is applied to the passivation of SDD, the leakage current is reduced to the order of nA.展开更多
文摘太阳能的应用是解决能源与环境问题的有效途径,而高转换效率低成本,易于产业化的高效电池技术是太阳电池发展的目标。近年来高转换效率技术层出不穷,例如SE电池(Selective emitter Cell),MWT电池(Metal warp through cell)和EWT电池(Emitter Warp through cell)等。这些高效电池均采用了良好的钝化技术。而常规晶硅太阳电池由于没有采用背场钝化技术,只使用铝背场,而经过烧结形成的铝硅合金背表面在减少复合和背反射效果方面有很大的局限性,并且铝硅合金区本身即高复合区,限制了电池效率的进一步提高。因此为了进一步提高开路电压及短路电流,对硅基背表面进行钝化是很有必要的。通过试验,着重比较了SiNx背场钝化层和SiO2背场钝化层对电池电性参数的影响和变化趋势。通过对电池片IQE分析发现,在使用了SiO2或SiNx背场钝化层后,长波区域的IQE响应相比正常电池片有明显提升,说明SiO2或SiNx确实起到钝化作用。而再对电性参数分析后发现,SiO2与SiNx相比可以有效提高电池的Rsh,降低反向电流。同时在EFF测试方面,SiO2与SiNx相比,也具有一定的优势。
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51602340,51702355,and 61674167)the Natural Science Foundation of Beijing Municipality of China(Grant No.4192064)+1 种基金the National Key Research Program of China(Grant Nos.2018YFB1500500 and 2018YFB1500200)the JKW Project of China(Grant No.31512060106)。
文摘Based on the surface passivation of n-type silicon in a silicon drift detector(SDD), we propose a new passivation structure of SiO2/Al2O3/SiO2 passivation stacks. Since the SiO2 formed by the nitric-acid-oxidation-of-silicon(NAOS)method has good compactness and simple process, the first layer film is formed by the NAOS method. The Al2O3 film is also introduced into the passivation stacks owing to exceptional advantages such as good interface characteristic and simple process. In addition, for requirements of thickness and deposition temperature, the third layer of the SiO2 film is deposited by plasma enhanced chemical vapor deposition(PECVD). The deposition of the SiO2 film by PECVD is a low-temperature process and has a high deposition rate, which causes little damage to the device and makes the SiO2 film very suitable for serving as the third passivation layer. The passivation approach of stacks can saturate dangling bonds at the interface between stacks and the silicon substrate, and provide positive charge to optimize the field passivation of the n-type substrate.The passivation method ultimately achieves a good combination of chemical and field passivations. Experimental results show that with the passivation structure of SiO2/Al2O3/SiO2, the final minority carrier lifetime reaches 5223 μs at injection of 5×10^(15) cm^(-3). When it is applied to the passivation of SDD, the leakage current is reduced to the order of nA.
