929300 EQE external quantum efficiency 1558 1799909 EQEmax external quantum efficiency 189 2105709 etaEQE external quantum efficiency 6 1953348 eta ex external quantum efficiency 5 2105974 eta ext external quantum efficiency 4 1901529 EQEEL external quantum efficiency 3 1963790 etaEQE,max external quantum efficiency 2 938231 eta external quantum efficiency 1 2648667 etaE external quantum efficiency 1