The charge density of a TiO2 film deposited on a SiO2-passivated silicon wafer is determined. The TiO2 is deposited by atmospheric pressure chemical vapor deposition at 400 degrees C, and the SiO2 is grown thermally at 950 degrees C. This TiO2-SiO2 stack is a useful coating for the front surface of a silicon solar cell, as it has a high optical transmission and a low density of interface states D-it(E) at the SiO2-Si interface. While these properties are beneficial to high efficiency solar cells, so too is a large charge density, as what occurs in Si3N4-SiO2 (+10(12) cm(-2)) and Al2O3-SiO2 (-10(13) cm(-2)) stacks. The D-it(E) and charge density of TiO2-coated and SiO2-passivated silicon are evaluated by capacitance-voltage and Kelvin probe measurements. The charge density of the TiO2 is within the conservative limits of -8.5 and -1 x 10(11) cm(-2) after deposition and of -10 and +1 x 10(11) cm(-2) after a subsequent 800 degrees C oxygen anneal. Photoconductance measurements suggest that the dangling-bond defects at the SiO2-Si interface are predominantly donorlike and, hence, that the change density in the TiO2 is closer to the upper limits (less negative); this charge is too small to benefit solar cells. (C) 2009 The Electrochemical Society. [DOI:10.1149/1.3216029] All rights reserved.