Kinetics ofa-Si:H bulk defect anda-Si:H/c-Si interface-state reduction

Abstract

Low-temperature annealing of hydrogenated amorphous silicon (a-Si:H) is investigated. An identical energy barrier is found for the reduction of deep defects in the bulk of a-Si:H films and at the interface such layers form with crystalline Si (c-Si) surfaces. This finding gives direct physical evidence that the defects determining a-Si:H/c-Si interface recombination are silicon dangling bonds and that also kinetically this interface has no unique features compared to the a-Si:H bulk.

Surface passivation of c-Si for silicon heterojunction solar cells using high-pressure hydrogen diluted plasmas

“…14 De Wolf et al obtained similar results in the past, 33 although with shorter τ eff , for deposition temperatures <200…”

“…with reduced nano-sized void formation during the initial stage of the growth, are beneficial from an electronic passivation perspective. 33 At the same time the high hydrogen content is reducing the defect density in the layers and the stacks approach a similar τ eff after post-deposition annealing.…”

“…It has been shown that post-deposition annealing can provide information about the abruptness of the interface. 32,33 When epitaxial growth has occurred at the a-Si:H/c-Si interface annealing at this temperature reduces the τ eff , while in presence of an abrupt transition at the a-Si:H/c-Si interface annealing increases the τ eff . On the other hand, this temperature is well below the hydrogen effusion temperature which is expected to be at ∼300…”

Light-induced performance increase of silicon heterojunction solar cells

“…2 In recent years, a-Si:H layers also garnered significant attention, thanks to their excellent crystalline silicon (c-Si) surface passivation properties, even when only a few nm thin. [3][4][5][6][7][8] This property is exploited with remarkable success for passivating-contact fabrication in silicon heterojunction (SHJ) solar cells, [9][10][11][12][13][14][15][16][17][18][19][20][21][22] with reported conversion cell efficiencies as high as 26.3%. 23 For any solar cell technology, an important criterion for ultimate device performance is its stability under prolonged light exposure.…”

Damage at hydrogenated amorphous/crystalline silicon interfaces by indium tin oxide overlayer sputtering

“…15,16 The dangling bonds may be created from plasma luminescence (visible or UV) or electron or particle bombardment (neutrals and ions from the gas phase, the sputtering target and their compounds). 6 In our experiments, the TCO deposition time strongly influences the induced damage, as shown in Fig.…”