Approach for Al2O3 rear surface passivation of industrial p-type Si PERC above 19%

作者：Vermang Bart^*; Goverde Hans; Tous Loic; Lorenz Anne; Choulat Patrick; Horzel Jorg; John Joachim; Poortmans Jef; Mertens Robert

来源：Progress in Photovoltaics: Research and Applications , 2012, 20(3): 269-273.

DOI：10.1002/pip.2196

• Si
• surface
• passivation
• Al2O3
• ALD
• PERC

Atomic layer deposition (ALD) of thin Al2O3 (=10?nm) films is used to improve the rear surface passivation of large-area screen-printed p-type Si passivated emitter and rear cells (PERC). A blister-free stack of Al2O3/SiOx/SiNx is developed, leading to an improved back reflection and a rear recombination current (J0,rear) of 92 +/- 6?fA/cm2. The Al2O3/SiOx/SiNx stack is blister-free if a 700 degrees C anneal in N2 is performed after the Al2O3 deposition and prior to the SiOx/SiNx capping. A clear relationship between blistering density and lower open-circuit voltage (VOC) due to increased rear contacting area is shown. In case of the blister-free Al2O3/SiOx/SiNx rear surface passivation stack, an average cell efficiency of 19.0% is reached and independently confirmed by FhG-ISE CalLab. Compared with SiOx/SiNx-passivated PERC, there is an obvious gain in VOC and short-circuit current (JSC) of 5?mV and 0.2?mA/cm2, respectively, thanks to improved rear surface passivation and rear internal reflection.

• 出版日期2012-5