We studied the effective net charge density (Qeff) of strontium silicate (SrxSiOx+2, x = 1, 2, 3) films grown on silicon (Si) (100) substrates. The SrxSiOx+2 layers were deposited from a Sr2SiO4 polycrystalline target by pulsed laser deposition, and then annealed at 400–600 °C in an oxygen atmosphere with a tube furnace. The Qeff values of the SrxSiOx+2/Si (100) samples were obtained from the shift in the voltage of the flat band state in their capacitance–voltage curves. The SrxSiOx+2/Si (100) samples with a thickness of 15 nm annealed at 400 °C showed the maximum Qeff/q value of 1.03 × 1013 cm−2, where q is the elementary charge. With increasing annealing temperature, the SrxSiOx+2 layer penetrated into the Si (100) substrate. This penetration may degrade the interfacial properties and decrease the Qeff value of the layers. For all the samples, the charges concentrated near the SrxSiOx+2/Si (100) interface. Our results suggest that anion and cation migration plays an important role in charge generation at the SrxSiOx+2/Si (100) interface, consistent with the findings of a previously reported molecular dynamics calculation.
Aluminum acetylacetonate-based AlOx thin films were introduced as a low-cost, high-quality passivation layers for crystalline silicon solar cells. Films were formed by a spin coating method on p-type silicon substrates at 450°C in ambient air, O2, or water vapor (H2O/O2) for 15 or 120 min. XPS analysis confirms the AlOx formation and reveals a high intensity of interfacial SiOx at the AlOx/Si interface of processed wafers. Ambient H2O/O2 was found to be more beneficial for the activation of introduced AlOx passivation films which offers high lifetime improvements with a low thermal budget. Carrier lifetime measurements provides that symmetrically coated wafers reach 119.3 μs and 248.3 μs after annealing in ambient H2O/O2 for 15 min and 120 min, respectively.
We prepared HfO 2 /SiO 2 /Si(100) and Y 2 O 3 /SiO 2 /Si(100) structures by annealing of HfO 2 /Si(100) and Y 2 O 3 /Si(100) precursors which were fabricated by PLD. From the structure analysis by XPS, we defined the optimal annealing condition which SiO 2 layer was grown at the HfO 2 /Si and Y 2 O 3 /Si interfaces. The C-V curves of the samples annealed with the optimal condition (700℃, 1 hour) showed a flat band voltage shift in opposite directions. We consider that the shifts are due to dipoles with two different polarities formed by the difference of areal density of oxygen atoms at the HfO 2 /SiO 2 and Y 2 O 3 /Si interfaces.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.