A global overview of residential building energy consumption in eight climate zones

<p>This study provides a global overview and comparison of residential building energy consumption (RBEC) in 8 climate zones in order to provide a visible foundation for policymakers and decision-makers with respect to sustainable future levels of RBEC. A total of 31 countries and 14 provinces/municipalities within these 8 climate zones are furthermore grouped into 20 different regions based on income. Demographic statistics regarding housing and RBEC of these regions are collected for analysis in this study. The results indicate that: 1) RBEC per capita and per m² in most Organisation for Economic Co-operation and Development (OECD) countries has decreased over the past two decades; 2) in developing countries, such consumption does not follow the same pattern of change; 3) within each climate zone, RBEC per m² is not significantly different for regions and countries in the same income groups, but there is significant difference in RBEC per capita for different regions and countries, even within the same climate zone and income group; and 4) RBEC per capita and per m² in the same climate zone differ widely between different income groups.</p

Weak Epitaxy Growth of Phthalocyanine on Inducing Layers of Fluorinated 5,5″-Bis(biphenyl-4-yl)-2,2′:5′,2″-terthiophene

Weak epitaxy growth (WEG) is an effective method in the preparation of high-mobility thin films of disk-like organic semiconductors. The growth behavior and quality of the epitaxial thin film are closely related to the inducing layers. Here, a series of fluorinated molecules, 5,5″-bis­(3′-fluoro-biphenyl-4-yl)-2,2′:5′,2″-terthiophene (<i>m</i>-F2BP3T), 5,5″-bis­(3′,5′-difluoro-biphenyl-4-yl)-2,2′:5′,2″-terthiophene (F4BP3T), and 5,5″-bis­(4′-fluoro-biphenyl-4-yl)-2,2′:5′,2″-terthiophene (<i>p</i>-F2BP3T) as well as a referenced molecule 5,5″-bis­(biphenyl-4-yl)-2,2′:5′,2″-terthiophene (BP3T), are introduced to serve as inducing layers for the epitaxy growth of phthalocyanine. Compared to the nonfluorinated inducing layer, the interactions between the fluorinated inducing layer and phthalocyanine might be relatively strong due to the potential existence of C–H···F weak hydrogen bonds. The growth behavior and mechanism of phthalocyanine on the fluorinated inducing layers are investigated by atomic force microscopy (AFM), grazing incidence X-ray diffraction (GIXD), selected area electron diffraction (SAED). According to the AFM and SAED, H₂Pc presents a selective epitaxy growth depending on the position of fluorine: epitaxy growth on <i>m</i>-F2BP3T and F4BP4T, and nonepitaxy growth on <i>p</i>-F2BP3T. Comparison of CuPc with F₁₆CuPc on monolayer <i>p</i>-F2BP3T further revealed that the uncommon nonepitaxy growth behavior of H₂Pc (CuPc) on <i>p</i>-F2BP3T mainly originates from the enhanced interactions between the two types of molecules. As a consequence, the capability of molecules orienting themselves along the surface channel is decreased; meanwhile, the demand of the upper limit of the lattice mismatch is more rigorous for commensurate epitaxy. Finally, the oriented nucleation of H₂Pc (CuPc) on monolayer <i>p</i>-F2BP3T is affected, and netlike crystals are formed. The sudden change of H₂Pc (CuPc) from multiorientation on monolayer to just one orientation on double-layer <i>p</i>-F2BP3T suggests that there is a critical lattice mismatch value for commensurate epitaxy in WEG when the molecule–substrate interactions are enhanced

Growth of Highly Oriented Ultrathin Crystalline Organic Microstripes: Effect of Alkyl Chain Length

The growth of organic semiconductor with controllable morphology is a crucial issue for achieving high-performance devices. Here we present the systematic study of the effect of the alkyl chain attached to the functional entity on controlling the growth of oriented microcrystals by dip-coating. Alkylated DTBDT-based molecules with variable chain lengths from <i>n</i>-butyl to <i>n</i>-dodecyl formed into one-dimensional micro- or nanostripe crystals at different pulling speeds. The alignment and ordering are significantly varied with alkyl chain length, as is the transistor performance. Highly uniform oriented and higher-molecular-order crystalline stripes with improved field-effect mobility can be achieved with an alkyl-chain length of around 6. We attribute this effect to the alkyl-chain-length-dependent packing, solubility, and self-assembly behavior

Quasi-Layer-by-Layer Growth of Pentacene on HOPG and Au Surfaces

High-resolution scanning tunneling microscopy (STM) is a promising method for characterizing organic semiconductors to obtain a deep understanding of organic semiconductor physics. However, organic films on conductive single-crystal substrates, which are required for STM, usually present different growth behaviors than the films on inert substrates such as SiO₂. Here, we reported a simple modification method for modulating the organic semiconductor film growth on the highly oriented pyrolytic graphite (HOPG) and Au(111) substrates and investigated the detailed morphology evolution. Self-assembled monolayers (SAMs) fabricated from vacuum deposition and solution processing were introduced on these conductive substrates. Pentacene, a prototypical organic semiconductor, presented quasi-layer-by-layer growth on HOPG or Au(111) sufaces modified with solution-processed alkane monolayer. The pentacene film resembled the upright packing and terraced morphology but with larger grain size than that of thin-film phase on SiO₂. The introduced <i>n</i>-dotriacontane layer decreased the interaction between pentacene adsorbates and the active substrate and provided a lower surface energy which supported the upright orientation of pentacene. Modification of the substrates with alkanes provides a feasible approach to grow high-quality organic thin films that are suitable for characterization down to the molecular level. Additionally, this approach is effective for two-dimensional substrate materials such as graphene and is not limited to single-crystal substrates

Influence of Solid-State Packing of Dipolar Merocyanine Dyes on Transistor and Solar Cell Performances

A series of nine dipolar merocyanine dyes has been studied as organic semiconductors in transistors and solar cells. These dyes exhibited single-crystal packing motifs with different dimensional ordering, which can be correlated to the performance of the studied devices. Hereby, the long-range ordering of the dyes in staircase-like slipped stacks with <i>J</i>-type excitonic coupling favors charge transport and improves solar cell performance. The different morphologies of transistor thin films and solar cell active layers were investigated by UV–vis, AFM, and XRD experiments. Selenium-containing donor–acceptor (D–A) dimethine dye <b>4</b> showed the highest hole mobility of 0.08 cm² V^–1 s^–1. BHJ solar cells based on dye <b>4</b> were optimized by taking advantage of the high crystallinity of the donor material and afforded a PCE of up to 6.2%