Small-molecule organic solar cells with improved stability

Solar cells utilizing small molecular weight organic semiconductors

“…135 Despite this fact, to date there have been relatively few studies of the lifetime of organic solar cells based upon small molecular weight materials, 98,136,137 where lifetimes of greater than 1500 h (η P = 50% of original value) have been demonstrated for unencapsulated devices.…”

“…[93][94][95] Also, recently other materials have been proposed as EBL materials which are both organic and inorganic. [96][97][98] The multiple functions of the EBL layer are still a matter of continuing research. 99,100 Recently, by comparing the device performance and interface energy levels of two different EBL materials, 93 it was confirmed that charge transport in BCP is due to damage induced during deposition of the cathode (shown in the EBL layer of Figure 8), while using an EBL with a low IP allows for hole transport to the C 60 /EBL HJ and to direct recombination with electrons photogenerated in the acceptor layer, and this recombination mechanism was also determined for that of the BCP EBL.…”

J–V characteristics of dark and illuminated classical and inverted organic solar cells based on the CuPc/C60 heterojunction

“…The anode is ITO/Au (0.5 nm), MoO 3 /Ag/ MoO 3 and MoO 3 /Ag/ MoO 3 /Au. The electron donor is CuPc, the electron acceptor is C 60 , the buffer layer is Alq 3 [11,12]. The whole organic cells were prevented from air contamination by an amorphous selenium thin film [8,9,12].…”

“…The cathode buffer layer (CBL) is a large band gap material, such as bathocuproine (BCP) [10] or aluminium tris(8-hydroxyquinoline) (Alq 3 ) [11,12], it is called exciton blocking layer (EBL). The EBL, not only blocks the excitons far from the cathode where they can be quenched, but, also, prevent from damage the electron acceptor film during cathode deposition.…”

On the influence of the exciton-blocking layer on the organic multilayer cells properties

“…However, with ti me, BCP tends to crystallize, which induces some OSCs performance degradation [ 4]. So others materials have been probed as EBL such as more conductive materials [5] or more stable such as the aluminium tris(8 -hydroxyquinoline) (Alq 3 ) [4,[6][7].…”