Morphology characterization in organic and hybrid solar cells

Abstract

Organic and hybrid organic-inorganic photovoltaics are among the most promising options for lowcost and highly scalable renewable energy. In order to fully realize the potential of these technologies, power conversion efficiencies and stability will both have to be improved beyond the current state-ofthe-art. The morphology of the active layer is of paramount importance in the photon to electron conversion process in organic and hybrid solar cells, with all length scales, from molecular ordering to intradevice composition variability, playing key roles. Given the central influence of morphology, characterizing the structure of these surprisingly complex material systems at multiple length scales is one of the grand challenges in the field. This review addresses the techniques, some of which have only recently been applied to organic and hybrid photovoltaics, available to scientists and engineers working to understand-and ultimately improve-the operation of these fascinating devices.

Structure and Morphology Control in Thin Films of Conjugated Polymers for an Improved Charge Transport

“…However, clarifying the detailed, bottom-up relationship between materials and performance has been always challenging since the discovery of semi-conducting conjugated polymers. After the related research for several decades, a great progress has been made in this field [2,3,[19][20][21][22][23][24][25][26][27][28][29], i.e., proposing more clear and efficient synthesis guidelines, concluding principles to improve morphological order and revealing the importance of morphological and structural features in films to the final performance. Now, synthesis of more efficient π-conjugated systems and improvement of order in films have become the essential problems for the development of opto-electronic functional conjugated polymers in terms of chemistry and physics, respectively.…”

Diffusion Length Mapping for Dye-Sensitized Solar Cells

“…It has long been recognized that the spatial distribution of local parameters, such as optical absorption, electroluminescence, diffusion length, etc., can provide valuable information on the stability, performance and degradation prediction of solar cells [1,2]. Moreover, spatial visualization of these properties is crucial to better address the up-scaling procedure that every photovoltaic technology has to tackle [3].…”

Morphological Control Agent in Ternary Blend Bulk Heterojunction Solar Cells

“…Therefore, the BHJ solar cell to date holds the leading PCE values of OPV system around 7%-11% in lab-scale and takes the majority of OPV studies [1]. Some important subjects regarding the advance of OPV over the past decades can be referred to the comprehensive review articles, i.e., materials development [2][3][4][5], morphology [1,[6][7][8][9][10], device physics [11][12][13][14], device structure [15].…”

“…Various strategies have been reported to tailor the morphology from local-scale (molecular ordering/conformation) to global-scale (domains/networks in tens and hundreds of nanometer) e.g., thermal annealing [16][17][18][19], solvent vapor annealing [17,20], type of processing solvents [21], incorporation with solvent additives [1,22], etc. These morphological control methods and associated characterization techniques have also been comprehensively reviewed [1,[6][7][8][9][10]23,24]. In our previous review article, we systematically summarized the effects of incorporating solvent additives which has found to be effective in a variety of BHJ systems [1].…”