Based on theories of inter-organizational knowledge flows and organizational learning, we argue that intensively accessing knowledge from a limited number of external channels, i.e., open search depth, can facilitate the innovating company's incremental innovation performance. We also argue that accessing knowledge from a broad range of external channels, i.e., open search breadth, can enhance the innovating firm's radical innovation performance. Using hierarchical regressions to analyze survey data collected from 184 Taiwanese electronic product manufacturers, we found that open search depth is positively related to the innovating firm's incremental innovation performance, and that open search breadth is positively related to radical innovation performance. As our results differ from those of previous studies, we provide a possible explanation for the discrepancy. Examining the effect of open search strategy from a theoretical angle not yet explored before, our findings can contribute to both scholarly and practitioner knowledge of open innovation.

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IntroductionIn recent decades, the world has come to a consensus that new green energy sources are vital for sustainable development. Solar energy has been regarded as an alternative source of energy supply. Photovoltaic (PV) technology has progressed for decades with massive efforts devoted. Alternative technologies for photon to electron power conversion include, for instance, This review presents various hole transport layers (HTLs) employed in perovskite solar cells (PSCs) in pursuing high power conversion efficiency (PCE) and functional stability. The PSCs have achieved high PCE (over 23%, certified by NREL) and more efforts have been devoted into research for stability enhancement. Inorganic HTLs become a popular choice as selective contact materials because of their intrinsic chemical stability and low cost. HTLs and electron transport layers (ETLs) are critical components of PSCs due to the requirement to create charge collection selectivity. Herein the authors provide an overview on inorganic HTLs synthesis, properties, and their application in various PSCs for both mesoporous and planar architectures. InorganicHTLs with appropriate properties, such as proper energy level and high carrier mobility, can not only assist with charge transport, but also improve the stability of PSCs under ambient conditions. The importance of interfacial chemistry and interfacial charge transport is further addressed to understand the underlying mechanism of related degradation and carrier dynamic. It is expected that the success of the inorganic HTL in PSCs can stimulate further research and bring real impact for future photovoltaic technologies.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/admi.201800882. super-mesostructure Al 2 O 3 scaffold, achieving a PCE above 9% [6] and 10%, [7] respectively.

New zinc porphyrins Y2 and Y2A2 have been utilized in perovskite solar cells specifically as hole-transporting materials (HTMs) rather than photosensitizers. The combination of MAPbI3 as photosensitizer and porphyrins as HTMs is a potential alternative to well-known MAPbI3/Spiro-OMeTAD hybrids owing to high performance and versatility toward molecular engineering of porphyrin families. A high efficiency of 16.60% is achieved by n-butyl tethered Y2 HTM (V OC = 0.99 V; J SC = 22.82 mA cm–2) which is comparable to that of Spiro-OMeTAD of 18.03% (V OC = 1.06 V; J SC = 22.79 mA cm–2). Both materials possess similar highest occupied molecular orbital level and the same order of magnitude of hole mobility at 10–4 cm2 V–1 s–1. The slightly poorer performance of 10.55% (V OC = 1.01 V; J SC = 17.80 mA cm–2) is obtained for n-dodecyl tethered Y2A2 HTM. This is believed to stem from more surface pinholes when deposited on perovskite leading to an order of magnitude slower mobility.

by modifying the deposition techniques. Currently, solution-processed and vaporassisted routes dominate the fabrication approaches for perovskite absorber layer.Nowadays, solution-processed spincoating method is still the major approach to synthesize perovskite fi lm for high effi ciency PSCs. [4][5][6] Various deposition routes have been developed to prevent the unwanted phenomena such as fast crystallization rate and incomplete coverage which resulted in poor quality perovskite fi lm. For instance, solvent engineering using toluene, [ 6 ] diethyl ether, [ 7 ] or other solvents [ 8 ] was conducted to produce shiny mirror-like perovskite fi lm with effi cient perovskite solar cells and excellent reproducibility. Despite the extremely high device effi ciency achieved by solution-processed approach, fabrication of large-area perovskite module for commercial purpose remained challenging with spin-coating process.Vapor-based deposition technique for perovskite fi lm preparation is considered as a promising approach which not only prevents fast reaction rate but also benefi ts for large-scale perovskite module fabrication. With regard to the reduction of the reaction rate for pin-hole-free high-quality absorber layer, several works applying various vapor-assisted deposition techniques for perovskite (APbX 3 , A = CH 3 NH 3 or CH(NH 2 ) 2 , X = Cl, Br, or I) layer fabrication have been reported recently. In 2013, a dualsource coevaporation deposition of organic CH 3 NH 3 I (MAI) and inorganic PbCl 2 in high vacuum chamber successfully created a uniform fl at CH 3 NH 3 PbI 3-x Cl x layer. A remarkable PCE of 15% [ 8 ] incorporating with spiro-MeOTAD has been achieved. The inverted planar perovskite solar cells incorporating with organic hole blocking layer have also been reported applying dual-source evaporation route using PbI 2 (250 °C) and MAI (70 °C) as evaporation sources and the effi ciency of solar cells was 12%.[ 9 ] The efficiency was then further optimized up to 14.8% [ 10 ] (0.065 cm 2 ) for small-area device and 10% for larger-area device (≈1 cm 2 ). Some similar works using dual-source coevaporation method have been reported. [ 11,12 ] Since then a modifi ed layer-by-layer sequential vacuum evaporation method, which thermally sublimated PbCl 2 and MAI one after another onto the PSS:PEDOT/ITO substrate, was fi rst applied to form CH 3 NH 3 PbI 3-x Cl x absorber layer. The photovoltaic performance of solar cells reached 15.4%. [ 13 ] Similar work was reported by introducing a graphite vessel rather than high vacuum chamber to sequentially evaporate PbI 2 /MAI and obtained a best PSCs of 13.7%. [ 14 ] However, owing to their material properties for MAI and PbCl 2 , controlling the codeposition Vapor-based deposition technique is considered as a promising approach for preparing a high-quality and uniform perovskite thin fi lm. With evolution from coevaporation deposition to a low-pressure vapor-assisted solution process, both energy budget and reaction yield for perovskite fi lm fabrications are improved. In th...