Investigation of various surface passivation layers using oxide/nitride stacks of silicon solar cells

In this work, three different surface passivation technologies are used: classical thermal oxidation (CTO), rapid thermal oxidation (RTO) and silicon nitride using PECVD. Eight combined passivation schemes including SiO 2/SiNx stacks are investigated on 1 ohm cm FZ silicon without and with emitter (100 ohm/ and 40 ohm /). SiO2/SiNx stack passivation results in excellent lifetime of 1361 µs without emitter and shows as a good passivation quality as CTO (300-400 µs) for 100 ohm/ emitter. The RTO/SiNx stack layers are used to passivate front and rear surfaces of the solar cells. The planar RTO/SiNx cell has a very high V(ind oc) of 675.6 mV. However, the Jsc and FF of the RTO/SiNx cells are lower than those of CTO cells. The main reasons of J(ind sc) and FF losses are also discussed.