What current does $${\text{I}} = {\text{Aq}}\left( {\frac{{{{\text{D}}_{\text{P}}}}}{{{{\text{L}}_{\text{P}}}{{\text{N}}_{\text{D}}}}} + \frac{{{{\text{D}}_{\text{n}}}}}{{{{\text{L}}_{\text{n}}}{{\text{N}}_{\text{A}}}}}} \right){\text{n}}_{\text{i}}^2,$$      represent in p-n junction diode? (Where the symbols have their usual meaning)