Surface & Quantum Efficiency Degradation of Multicrystalline Solar Cell in Shipping Process
SURFACE & QUANTUM EFFICIENCY DEGRADATION OF MULTICRYSTALLINE SOLAR CELL IN SHIPPING PROCESS
Chia-Cheng Chou*1), Der-Ray Huang*1)
*1Dept. of Opto-Electronic Engineering, National Dong Hwa University
Abstract
This study described the deterioration by performance of power, variance of surface and quantum efficiency (QE) in multicrystalline silicon solar cell (mc-Si solar cell) after vibration test which was simulated under the condition of land & air transportation. The vibration test follows some procedures from an unpublished draft of one developing international Standard. Mechanical defects on the surface of solar cell were obviously inspected by recognizable patterns evolving, shown from the method of electroluminescence (EL) imaging. The patterns were classified into 7 types by symptoms of crack/micro-crack. On the other hand, quantum efficiency variances of cell were measured in incident photon-to-electron conversion efficiency (IPCE), i.e. IPCE performance drop was found indeed in spectrum as 23.7%. After vibration test, total breakage rate is near 1% and some specific cells had 3% power loss in I-V measurement. EL images showed the sufficient evidences of defect’s growth due to mc-Si cells experienced vibration response during transshipment simulation. Furthermore, this applied research provided a common vibration test from a pre-normative Standard, and two nondestructive test method, EL and QE/IPCE to evaluate the damaged spot on mc-Si solar cells. Result shall also be considered as one key point to improve transportation package as well in the future.
Introduction
Photovoltaic modules (PV modules) are supposed to have a lifetime of more than 25 years. Under the global demand, the market competition of solar cell is more and more urgent in recent years. Hence, the PV industry tends to improve the quality and reduce the cost of products. Although the PV industry had been developed over 30 years, and it still does not exist a testing
Chia-Cheng Chou*1), Der-Ray Huang*1)
*1Dept. of Opto-Electronic Engineering, National Dong Hwa University
Abstract
This study described the deterioration by performance of power, variance of surface and quantum efficiency (QE) in multicrystalline silicon solar cell (mc-Si solar cell) after vibration test which was simulated under the condition of land & air transportation. The vibration test follows some procedures from an unpublished draft of one developing international Standard. Mechanical defects on the surface of solar cell were obviously inspected by recognizable patterns evolving, shown from the method of electroluminescence (EL) imaging. The patterns were classified into 7 types by symptoms of crack/micro-crack. On the other hand, quantum efficiency variances of cell were measured in incident photon-to-electron conversion efficiency (IPCE), i.e. IPCE performance drop was found indeed in spectrum as 23.7%. After vibration test, total breakage rate is near 1% and some specific cells had 3% power loss in I-V measurement. EL images showed the sufficient evidences of defect’s growth due to mc-Si cells experienced vibration response during transshipment simulation. Furthermore, this applied research provided a common vibration test from a pre-normative Standard, and two nondestructive test method, EL and QE/IPCE to evaluate the damaged spot on mc-Si solar cells. Result shall also be considered as one key point to improve transportation package as well in the future.
Introduction
Photovoltaic modules (PV modules) are supposed to have a lifetime of more than 25 years. Under the global demand, the market competition of solar cell is more and more urgent in recent years. Hence, the PV industry tends to improve the quality and reduce the cost of products. Although the PV industry had been developed over 30 years, and it still does not exist a testing
References: [4] “Standard Test Method for Random Vibration Testing for Shipping Containers”, ASTM International Standard D4728, Philadelphia, PA, USA, 2006. [5] MIL-STD-810,” Department of Defense Test Method Standard for Environmental Engineering Considerations and Laboratory Tests”, 2008.