Organic solar cells have the potential to be portable power sources that are light-weight, flexible, and inexpensive. However, the highest power conversion efficiency for organic solar cells to date is ~8%, and most high-efficiency solar cells have an area of less than 1 cm². This thesis advances the field of organic solar cells by studying the physics and engineering of the devices to understand the reverse saturation current, which is related to efficiency, and the effects of area scaling. The most commonly accepted models to describe the physics of organic photovoltaic devices are reviewed and applied to planar heterojunction solar cells based on pentacene / C60 as a model system. The equivalent circuit model developed for inorganic solar cells is shown to work well to describe the behavior of organic devices and parameterize their current-voltage characteristics with five parameters. Changes in the parameters with different material combinations or device structures are analyzed to better understand the operation of the presented organic solar cells. A one-dimensional diffusion model for the behavior of excitons and treatment of the organic layers as planes is demonstrated to adequately model the external quantum efficiency and photocurrent in pentacene / C60 solar cells. The origin of the open-circuit voltage is studied using cells with different electrodes and different donor materials. While changing the electrodes does not affect open-circuit voltage, it is greatly modified by changes in the donor. Tests with additional semiconductors show the change in open-circuit voltage is not consistent from donor to donor as the acceptor is varied, suggesting a more complex relation than just the difference in energy levels. Study of the temperature dependence of the equivalent circuit parameters shows that the reverse saturation current, which has a significant role in determining the open-circuit voltage, has a thermally activated behavior. From this behavior, the reverse saturation current is related back to charge transfer at the donor / acceptor heterojunction to suggest that both the effective energy barrier presented by the energy levels and the electronic coupling are important in determining the reverse saturation current and open-circuit voltage. This marks a shift from just considering a built-in voltage or the energy levels to also considering the electronic coupling of the donor and acceptor materials. Temperature-dependent performance characteristics are also used to show key differences between organic and inorganic devices. Finally, the effect of area scaling is explored with pentacene / C60 solar cells having areas of 0.11, 7, and 36.4 cm². Analysis with the equivalent circuit model shows that performance decreases as area increases because of an increasing series resistance presented by the transparent electrode. A metal grid, to provide low resistance pathways for current, fabricated on top of the transparent electrode is proposed to reduce the effective resistance. The grid is unique in that it is placed between the electrode and the semiconductor layer and must be passivated to prevent shorts through the thin semiconductor to the back metal electrode. Analysis of the grid predicts greatly reduced series resistance, and experimental results show reduced resistance and improved performance for the 7 cm² and 36.4 cm² devices when including the grid.

Satellite imagery and volume-area scaling are used to asses the glacier area and ice volume of Iceland from the Little Ice Age maximum to present day, obtaining a final result in sea level rise between 1890 - 2015. The Little Ice Age was a time of regional cooling, with glaciers reaching their maximum extent (~1890 for Iceland) with warming and glacier retreat after this period ended. Ice volume estimates are important to know due to their relevance in potential sea level rise calculations. Understanding both of these estimations for Iceland connects the impact a changing climate has on regional and global scales. Different scaling parameters used in the volume-area scaling approach to determine ice volume and ultimately sea level equivalents highlight the range of estimates acquired and point out the need in choosing appropriate values based on glacier region. A comparison to using mass balance measurements for volume estimates is also noted, showing differences in ice volume loss over past and present time periods. The Icelandic glacier area for present day is an updated value from previous studies at 10,803 ± 83 km2 and a first ever reported Icelandic Little Ice Age maximum glacier area of 12,201 ± 91 km2. For potential sea level rise, it is found the most reliable estimate from the volume- area scaling assessment is 2.67 mm from the Little Ice Age maximum to present day, with a yearly contribution since 1890 of 0.02 mm. / Satellitbilder och volym-area skalningsmetoden användes för att uppskatta glaciärarea och isvolym på Island från Lilla istiden till nutid, för att få fram hur stor höjningen av havsnivån varit under denna tidsperiod (1890 – 2015). Den lilla istiden var en tid av regional kylning då glaciärer nådde sin maximala utsträckning (~1890 för Island) följt av en snabb reträtt efter att denna period slutade. Uppskattningen av isvolym är viktigt att veta på grund av dess relevans i potentiella beräkningar av höjningen av havsnivån. Att förstå båda dessa uppskattningar för Island är kopplat till den påverkan ett förändrat klimat har på regional och global nivå. De olika skalparametrar som använts i volym-area skalningsmetoden för att bestämma volymen av is, och dess motsvarigheter i havsnivå, gav en rad av olika uppskattningar. Detta pekar på behovet att välja ett lämpligt parametervärde baserat på glaciärregionen. En jämförelse med att använda mätningar av massbalans för volymuppskattningar gjordes också, vilket visar skillnader i isvolymförlust över tidigare och nuvarande tidsperioder. Dagens värde på den isländska glaciärarean är uppdaterat från tidigare studier på 10,803 ± 83 km2 och den första rapporterade maximala isländska glaciärarean från Lilla istiden på 12,201 ± 91 km2. För potentiell höjning av havsnivån, har man funnit att den mest tillförlitlig uppskattning från volym-area skalningsmetoden är 2,67 mm från Lilla istidens maximum till nutid, med ett årligt bidrag sedan 1890 av 0,02 mm. (Översättning Cecilia Bayard.)