RSC Advances c4ra03465a PAPER Please check this proof carefully. O Our staff will not read it in detail after you have returned it. Translation errors between word-processor files and typesetting systems can occur so the whole proof needs to be read. Please pay particular attention to: tabulated material; equations; numerical data; figures and graphics; and references. If you have not already indicated the corresponding author(s) please mark their name(s) with an asterisk. Please e-mail a list of corrections or the PDF with electronic notes attached - do not change the text within the PDF file or send a revised manuscript. Corrections at this stage should be minor and not involve extensive changes. All corrections must be sent at the same time. Please bear in mind that minor layout improvements, e.g. in line breaking, table widths and graphic placement, are routinely applied to the final version. We will publish articles on the web as soon as possible after receiving your corrections; n no late corrections will be made. Please return your f final corrections, where possible within 4 48 hours of receipt by e-mail to: advances@rsc.org 1 Enhancing photovoltaics with broadband high- transparency glass using porosity-tuned multilayer silica nanoparticle anti-reflective coatings Joel Y. Y. Loh, Daniel P. Puzzo, Paul G. O'Brien, Geoffrey A. Ozin and Nazir P. Kherani * The performance of optoelectronic devices using glass envelopes can be improved substantially by the application of an effective anti-reflective coating. In this paper, we investigate the preparation of low index films through modulation of the porosity of silica nanoparticle films. Porosity variation is accomplished by introducing polystyrene porogen within colloidal silica nanoparticle films, which are deposited in a controlled manner, followed by pyrolysis of the porogen. Multilayer stacks of nanoparticle films with varying degrees of porosity were fabricated by sequentially spin coating and sintering various silica–polystyrene mixtures. The average transmittance (400–1000 nm) of Corning glass was improved from 91.0% to 95.2% using a three layer stack on one glass–air interface, and to 99.0% using three layer stacks on both interfaces – the highest reported values for facile synthesized multilayer structures. Utilization of the single and dual interface high transparency glass placed on a crystalline silicon solar cell leads to increased photocurrent densities by 4.0% and 6.0% absolute, respectively, relative to uncoated glass. 8 ART  C4RA03465A_GRABS 1 5 10 15 20 25 30 35 40 45 50 1 5 10 15 20 25 30 35 40 45 50