DIBPillar[n]arenes (n = 5, 6) were synthesized. They showed different host-guest properties with n-octyltriethyl ammonium hexafluorophosphate G due to their different cavity sizes. DIBpillar[5]arene showed no complexation with G, while DIBpillar[6]arene formed a 1:1 complex with G with an association constant of 334 (±24) M(-1) in chloroform. In this letter, the first pillar[6]arene crystal structure and the first investigation of the host-guest chemistry of pillar[6]arenes are reported.

An n-TiO2/n-Si isotype heterojunction is fabricated by depositing TiO2 thin films onto n-Si substrates. Obvious photovoltaic behaviors are observed in this isotype heterojunction. The open circuit voltage and short circuit current of the heterojunction can reach 123 mV and 20 µA/cm 2 , respectively. The mechanism for the photovoltaic behaviors can be understood in terms of the band alignment of the heterojunction. The results reported may provide a feasible route to easily available and low-cost isotyped photovoltaic devices.

Performance of the devices is significantly influenced by the charge balance between holes and electrons since the excess of one type over the other would lead to an increase in current but no emission contribution. The device performances were dramatically enhanced by using a mixed emitting layer of NPB and Alq 3 molecules, placed between pure NPB and Alq 3 layer. Comparing with the conventional heterostructure the turn-on voltage was reduced from 7v to 4v and the V--L characteristics was also improved by mixing hole and electron transporting layers. By changing the weight ratio of NPB and Alq 3 the spectrum have 33nm shift and the CIE coordinates have relevant change.