The analysis of dark current‐voltage (I‐V) characteristics of Al/chlorophylla/Ag cells at room temperature with respect to the elucidation of conduction mechanisms and evaluation of cell parameters is presented. It is seen that the presence of series and shunt resistances can considerably affect theI‐Vplots. It is therefore important to remove their effects for correct and meaningful analysis of theI‐Vcurves. The results suggest that for Al/Chla/Ag cells with microcrystalline Chla∼3000 A˚ thick, the conduction mechanism for voltages between 0.53 and 1 V can be described by a modified Shockley equation from which the values ofRs,Rsh,n, andI0obtained are 3.2×104&OHgr;, 1.7×109&OHgr;, 1.74, and 2.4×10−15A, respectively.Rsis most likely due to the combined effect of bulk Chlaand the electrodes, particularly the insulating layer of Al2O3that is formed as a result of oxidation of Al in air. For higher forward biases, i.e., between 1 and 2 V, the current transport is due to the space‐charge‐limited current in presence of exponentially distributed traps. The density of traps obtained is ∼1018cm−3. Because of the breakdown of Al/Chla/Ag cells at fields higher than 107V m−1, the transition voltage to observe the trap‐filled‐limit situation was not possible. For a low‐bias region, the conduction mechanisms seem to be dominated by Schottky emission over an Al/Al2O3barrier; however, the temperature dependence ofI‐Vcharacteristics is necessary to confirm this. The barrier Al/Al2O3calculated is ∼1.17 eV.