Organic photovoltaics (OPV) has attracted widespread attention and research as a promising renewable energy technology due to its low-cost, high-volume manufacturing potential and rapid advances in their power conversion efficiency of .1 Bulk heterojunctions (BHJs) are an important class of materials commonly used in OPV. BHJs are complex mixtures of an electron donating and an electron accepting organic semiconductors, phase separated at the nanometer scale. The photovoltaic performance of an organic BHJ material is highly dependent on its nanoscale morphology, which can be affected by a variety of factors, including the chemical structure of the organic semiconductors, the solvent and solvent additives, the fabrication methodology, and the environmental exposure. New measurement techniques and tools are needed to clarify the interaction between these factors affecting the morphology and the materials’ electronic properties, such as the carrier mobilities, charge concentrations, and recombination rate constants. To study these properties, researchers have typically utilized vertical solar cell structures similar to an actual OPV cell. A variety of techniques, including transient photocurrents,2 photo-generated charge extraction in a linearly increasing voltage (photo-CELIV),3 time-of-flight,4,5 impedance spectroscopy,6,7 time-resolved terahertz spectroscopy,8 time-resolved microwave conductivity,9 and dark-injection space charge limited current,10 have been successfully employed by many research groups. To complement these studies, we have developed techniques that measure the transport and recombination properties of organic BHJs along the in-plane axis, or lateral direction. This paper will summarize some of the important insights that can be obtained through lateral BHJ measurement techniques.