It is long recognized that the effective surface clean is critical for the increased performance of solar cell and semiconductor devices. In this contribution, we introduced the effectiveness of crystalline silicon surface clean by a simple ultraviolet-ozone (UVo) process by comparing it against the industry standard RCA and UV assisted deionized water (DiO3) techniques. Despite being simple, UV-ozone cleaning results in an effective surface passivation quality that is comparable to both RCA and DiO3 clean, i.e., saturation current density (J0) of 7 fA/cm2 compared to 5 fA/cm2 and 8 fA/cm2. In addition to the surface clean, we presented that both UVo and DiO3 oxides can be used as a highly-quality chemical passivation to the crystalline silicon substrate, but with UVo oxide offering an improved passivation than DiO3 oxide. Incorporating the UV}o oxide in between the interface of silicon and aluminum oxide or silicon nitride reduces J0 by >50%, compared to the interface without the UVo oxide.
