Mechanism of electrical passivation of Si surfaces with quinhydrone

Abstract

The ability of quinhydrone/methanol solutions to electrically passivate silicon surfaces with respect to minority carrier recombination has been confirmed. The p-benzoquinon has been found to be the active component of quinhydrone. It is the presence of ketones on opposite sides of the ring that acts to passivate the surface, although the exact mechanism of passivation is not understood. The time dependence of the passivation suggests that it includes more than merely repairing damage on hydrogen terminated surfaces.

Radical-Driven Silicon Surface Passivation by Benzoquinone– and Hydroquinone–Methanol and Photoinitiators

“…In developing silicon-based photovoltaics with thinner substrates and higher efficiencies, an effective surface passivation that reduces the density of defect states and surface recombination losses is increasingly important. High temperature passivation using a silicon dioxide or a silicon nitride layer has a long history and is still the standard method used in industry. , In comparison, room temperature, solution-based electronic passivation by molecules like halides and quinones, especially quinhydrone (QHY) in alcohol (mostly methanol), is emerging, because of the easier and cheaper processing and superior electronic passivation effects. − …”

Stable chemical enhancement of passivating nanolayer structures grown by atomic layer deposition on silicon

“…This stability far exceeds that of HF or other acidic treatment of bare silicon. 37,38 Fig. 3(b) shows SRVs for Si/HfO 2 /Al 2 O 3 stacks with 1 nm HfO 2 activated at 450 °C and sequentially re-annealed in air in a tube furnace for 30 min at temperatures increasing in 50 °C intervals.…”