Applied Physics Letters · 2013 · 140 citations · 26 references
EngineeringMaterials EngineeringMaterials ScienceElectronic MaterialsSemiconductor DevicesSemiconductor MaterialsSemiconductor Device MaterialsSemiconductor HeterostructuresSemiconductor InterfacesSemiconductor PhysicsSemiconductor SurfacesSurface PassivationAmorphous SiliconCarrier LifetimeCrystalline SiliconPassivationPassivation Of SemiconductorsPassivation TreatmentsPlasma TreatmentVoid Formation
The impact of post-deposition hydrogen plasma treatment (HPT) on passivation in amorphous/crystalline silicon (a-Si:H/c-Si) interfaces is investigated. Combining low temperature a-Si:H deposition and successive HPT, a high minority carrier lifetime >8 ms is achieved on c-Si 〈100〉, which is otherwise prone to epitaxial growth and thus inferior passivation. It is shown that the passivation improvement stems from diffusion of hydrogen atoms to the heterointerface and subsequent dangling bond passivation. Concomitantly, the a-Si:H hydrogen density increases, leading to band gap widening and void formation, while the film disorder is not increased. Thus, HPT allows for a-Si:H band gap and a-Si:H/c-Si band offset engineering.
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