EFFECTIVE METHODS TO INCREASE THERMALSTABILITY OF SHALLOW EMITTER SOLAR CELLS WITH ALUMINIUM FRONT CONTACTS

摘要

Thermal degradation of metal contacts remains a serious problem of solar cell manufacturing. If Al is usedas a material for the emitter contact, thermal degradation is frequently caused by the so called "spiking effect". Thepurpose of this work is to study different technological approaches allowing to prevent this kind of thermal degradation. As a first approach we propose to use a tunnel oxide (TO) beneath the metal emitter contact. TO is destined to separate Al and Si from direct contact, preventing interdiffusion of materials during thermal processing. As a second approach, in order to increase the thermal stability of the textured emitter solar cells, AlSi alloy emitter contacts in combination with TO were used. To adjust the concentration of Si in AlSi layer, e-gun evaporation from two independent sources was performed.