The technology behind a large area array of flexible solar cells with a unique design and semitransparent blue appearance is presented. These modules are implemented in a solar tree installation at the German pavilion in the EXPO2015 in Milan/IT. The modules show power conversion efficiencies of 4.5% and are produced exclusively using standard printing techniques for large‐scale production.

Three fluorinated BsubPcs have been synthesized and characterized. Crystals suitable for XRD were grown by slow vapor diffusion and sublimation. Analysis of their crystal structures revealed a dimeric association of BsubPc units for F 5 BsubPc and columnar packing for F 12 BsubPc and F 17 BsubPc. Cyclic volatmmetry (CV) was used to probe the frontier orbital energy levels of these compounds in both dichloromethane and acetonitrile solution; however, only F 5 BsubPc underwent oxidative events, whereas all three compounds underwent reductive events. A -362 and -37 mV shift in the reductive peak potential was observed for peripheral and axial fluorination, respectively, as measured by cyclic voltammetry. Solution UV-vis absorption and photoluminescence spectra were measured in dichloromethane. All three compounds demonstrated air-stable n-type conductivity in single-carrier devices and extremely narrow orange EL emission with a fwhm of only ∼30 nm. F 5 BsubPc showed a maximum luminescence of 122 cd/m 2 at 8 V, with a maximum current efficiency of 0.03 cd/A, whereas the devices fabricated from F 12 BsubPc and F 17 BsubPc produced luminescence with a maximum value of <1 cd/m 2 .

Boron subphthalocyanines (BsubPcs) are an emerging class of high performing materials in organic electronics. Since the first use of chloroboron subphthalocyanine in an organic electronic device 6 years ago subphthalocyanines have shown potential as functional materials in organic light emitting diodes (OLEDs) and organic photovoltaics (OPVs). Here we review the material properties of chloroboron subphthalocyanine (Cl-BsubPc) and its use as an organic semiconductor. We then highlight our efforts toward derivatives of boron subpthalocyanine beyond Cl-BsubPc and discuss the impact of molecular design on the material properties and the performance of the BsubPc. Finally, we comment on the status of BsubPcs in the field of organic electronics and discuss how we believe future progress can be made.

Nine derivatives of chloro boron subphthalocyanine (Cl-BsubPc, 1) have been synthesized and characterized. Seven dimers of Cl-BsubPc have been synthesized by reaction with biphenol (2a), bisphenol A (2b), bisphenol F (2c), bisphenol O (2d), bisphenol P (2e), bisphenol S (2f) and bisphenol Z (2g). For comparison two monomeric phenoxy- (3a) and 4-methylphenoxy (3b) BsubPcs have also been synthesized. Crystals were grown for dimer 2c, whereas all attempts to grow crystals of the remaining dimers resulted in the formation of molecular glasses or amorphous precipitates. Analysis on the structure of 2c suggests that the rigidity and aromatic nature of the central bisphenolic directs the crystal packing. The solubility of the BsubPc dimers in a variety of common organic solvents was measured and compared to that of Cl-BsubPc (2) and monomers 3a and 3b. We have defined ranges for classifying BsubPc derivatives based on their solubility in these solvents: pigment < or = 1 x 10(-8) M, 1 x 10(-3) M < or = pigment-like > 1 x 10(-8) M, 1 x 10(-2) M < or = dye-like > 1 x 10(-3) M, and dye > 1 x 10(-2) M. From this Cl-BsubPc (1) and compounds 2a, 2b, 2c, 2e and 2g are pigment-like while compounds 2d, 2f, 3a and 3b are dye-like. None are exclusively pigments or dyes. In this first approximation of this dye versus pigment classification we have not considered other processes besides solvation which could be undesirable such as polymorphic changes or Ostwald ripening. We have concluded that derivatization of Cl-BsubPc (1) with bisphenols and phenols can be used to control the solubility of BsubPc derivatives. We have also concluded that Cl-BsubPc (1) should not be considered a dye rather is pigment-like in its solubility.

We report the rapid screening of phenoxyboronsubphthalocyanine (PhO-BsubPc) derivatives for sensitivity of their HOMO and LUMO energy levels (E H and E L) to substitution with electron-donating and electron-withdrawing functional groups using semiempirical methods. Subsequently, we have synthesized a selection of seven PhO-BsubPc derivatives, further modeled the seven derivatives using DFT methods, and measured or determined their respective E H and E L. We have used a combination of ultraviolet photoelectron spectroscopy (UPS), cyclic voltammetry (CV), and ultraviolet–visible (UV–vis) spectroscopy to correlate the computational predictions with experimental data. From these experimental and computational results, we have shown that E H and E L of PhO-BsubPcs are more sensitive to peripheral substitutions than to substitution on the axial phenoxylate. The frontier molecular orbitals, calculated using DFT methods, were found to be exclusively located on the boronsubphthalocyanine ligand among the seven PhO-BsubPc derivatives. A mathematical model correlating computational results with experimental data was determined which can be subsequently used to rapidly predict how structural factors influence the E H and E L to direct synthetic and engineering efforts.