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The Shockley-Queisser formulation is a guideline for solar cell technology. However, the SQ limit does not take into account underlying parameters such as material quality and optical design.  Defect such as **grain boundaries** can alter electronic properties \cite{Yan_2011} in a uncontrolled fashion. Pushing cell conversion efficiencies beyond 20% will require increasing VOC V_{OC}  beyond 1V. However the present pathway of processing optimization will likely yield VOC V_{OC}  and efficiency converging on 0.9 V and <20%, respectively. \cite{McCandless_2013}. Therefore engineer the photon dynamics and internal fluorescence of a PV cell is essential in reaching theoretical efficiency.