Surface passivation of high‐efficiency silicon solar cells by atomic‐layer‐deposited Al₂O₃

Abstract

Atomic-layer-deposited aluminium oxide (Al 2 O 3 ) is applied as rear-surface-passivating dielectric layer to passivated emitter and rear cell (PERC)-type crystalline silicon (c-Si) solar cells. The excellent passivation of low-resistivity p-type silicon by the negative-charge-dielectric Al 2 O 3 is confirmed on the device level by an independently confirmed energy conversion efficiency of 20Á6%. The best results are obtained for a stack consisting of a 30 nm Al 2 O 3 film covered by a 200 nm plasma-enhanced-chemical-vapour-deposited silicon oxide (SiO x ) layer, resulting in a rear surface recombination velocity (SRV) of 70 cm/s. Comparable results are obtained for a 130 nm single-layer of Al 2 O 3 , resulting in a rear SRV of 90 cm/s.464 J. SCHMIDT ET AL. Thermal SiO 2 (220 nm) 90 AE 20 91 AE 1 Al 2 O 3 (130 nm) 90 AE 20 90 AE 1 Al 2 O 3 (30 nm)/SiO x (200 nm) 70 AE 20 91 AE 1

Thin-film Sb2Se3 photovoltaics with oriented one-dimensional ribbons and benign grain boundaries

“…(100), (010), (110) and (120) planes) and minimize recombination loss. This is in striking contrast to most known photovoltaic absorbers, in which the breakage of covalent bonds introduces defect states and recombination centers at GBs [13][14][15] .…”

Passivation effects of atomic-layer-deposited aluminum oxide

“…In reality the value of S lies in-between (0 < S < S effmax ) depending on the chosen injection level (Δn) [8,11,12,27,28]. Table 3 presents the surface recombination velocities (SRV) extracted from the lifetime measurements using equation (5) for 200 μm thick wafers covered with the different dielectrics.…”

Effective passivation of Si surfaces by plasma deposited SiOx/a-SiNx:H stacks

“…Furthermore, the thermal stability ͑up to 850°C͒ of the stack was found to be very high, which can be ascribed to effective hydrogenation of the Si/ SiO x interface under influence of the SiN x layer. The results presented are especially timely because various lowtemperature passivation schemes, such as aluminum oxide ͑Al 2 O 3 ͒, [14][15][16] are currently under evaluation as replacements for the standard aluminum back surface field in solar cells with thinner Si wafers.…”