The claim that the second law of thermodynamics prevents reflected light from making objects brighter is a fundamental consequence of the conservation of energy and entropy principles (specifically, that passive reflection cannot increase radiance or luminance), making it a matter of common physical knowledge requiring no specific citation.
The claim follows directly from the second law of thermodynamics and basic radiometry (specifically, the invariance of basic radiance in passive optical systems), which states that an object cannot be made brighter or raise its temperature above that of the source via passive reflection. The retrieved papers discuss thermodynamics, quantum limits, and material sciences, but none directly evaluate this basic thermodynamic truism in a way that requires specific empirical citation.