deletions | additions       diff --git a/A_PV_will_reach_the__.md b/A_PV_will_reach_the__.md  index 9ed2047..dbaff6b 100644  --- a/A_PV_will_reach_the__.md  +++ b/A_PV_will_reach_the__.md 
...
The SQ limit is a guideline for solar cell technology. However, it does not take into account underlying parameters such as material quality and optical design.  A PV will reach the SQ it's theoretical  limit if it's material properties match the assumptions made to derive to derive this limit. Following made.  ollowing  we can compare these assumptions with real material conditions: * All incident light is absorbed below the band gap of the material, and each absorbed photon generates an electron-hole pair. This relates to the bandgap of a material and absorbtion mechanism.  * Only **radiative recombination** occurs. In reality there is always a degree of non-radiative process ocurring such as Shockley-Read-Hall, Auger and band to band (BB). These process strongly affect the cell’s performance depending on semiconductor bandgap, material quality, doping level, fabrication process, or injection level.\cite{Vossier_2015} SRH is due to various impurities and dislocations, these create energy levels within the band gap corresponding to neither donor nor acceptor levels. Auger is the dominating process at high carrier concentrations caused by heavy doping or high level injection, which ultimately affects the lifetime in efficency. Band to Band is to weakly absorbed photons that exit the semiconductor.   * **infinite mobility** and **perfectly reflecting contacts**, which relate to charge transport: Photons emitted internally are likely to be trapped, re-absorbed, and re-emitted, leading to photon recycling in a open-circuit. Real materials have a non-ideal back contact, so they will not benefit completely from the photon recycling that occurs in a ideal reflecting system. \cite{Miller_2012}, Real materials also have finite carrier mobility, which translate to series resistance losses.  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 \( V_{OC} \) beyond 1V. However the present pathway of processing optimization will likely yield \( V_{OC} \) 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.