Dependence of mobility and charge injection on active layer thickness of bulk heterojunction organic solar cells: PCBM:P3HT

Flexible Solution-Processed Electron-Transport-Layer-Free Organic Photovoltaics for Indoor Application

“…To understand the effect of different device architectures on photovoltaic performance, electron-only devices with ITO/PEI-Zn/active layer/EGaIn and ITO/PEI-Zn/active layer/PDINN/Ag structure were prepared and measured according to the space-charge limited current (SCLC) method. , At low positive voltages, the J – V curves are straight lines following Ohm’s law ( J ∝ V ), where the conductivity is determined by the background charge carriers. , At intermediate positive voltages, the concentration of injected free carriers surpasses that of the background charge carriers, resulting in the space-charge effect that restricts the current due to the accumulation of space charge. Furthermore, the current density shows a square law dependence with voltage ( J ∝ V 2 ), following the Mott–Gurney law as follows. − We show the J – V 2 curves at the SCLC stage in Figure d. μ normale = 8 d 3 9 ε 0 ε normalr J V 2 Here, μ e denotes the zero-field mobility of electrons, ε 0 denotes the vacuum permittivity, ε r denotes the relative permittivity of the active material, d denotes the blend film thickness, and V 2 = ( V appl – V bi ) 2 . V appl denotes the applied voltage and V bi denotes the built-in potential calculated via the work function difference.…”

Drastic performance improvement of indoor organic photovoltaics using a novel laminated homojunction hole-transport layer

“…, 0.1 V < V < 1.5 V) ohmic conduction with m = 1 was observed for both devices (ohmic region). 35,36 Corresponding to medium voltages ( i.e. , 1.5 V < V < 3 V), the current increased quickly for both devices, indicating a trap-filling occurrence (trap-filling region).…”

“…Corresponding to low voltages (i.e., 0.1 V < V < 1.5 V) ohmic conduction with m ¼ 1 was observed for both devices (ohmic region). 35,36 Corresponding to medium voltages (i.e., 1.5 V < V < 3 V), the current increased quickly for both devices, indicating a trap-lling occurrence (trap-lling region). The charge traps distributed in energy can be lled by gradually increasing the electric eld.…”

Characteristics of the Colorless Polyimide-Based Flexible X-ray Detector with Non-Fullerene Acceptor Polymer

“…To verify the reason for the increase in R q and R S while the electrical properties improved, the electron-transport properties of the detectors according to different receptors were characterized, and the J–V curve of the detector with a bias voltage of –3 to +3 V under dark condition was shown in Figure 7 a. Using curve fitting of the logarithmic J–V curve, the electron mobility (μ) and defect density were calculated using the space charge limited current (SCLC) model [ 22 , 23 , 24 , 25 ], using the Mott–Gurney Equation (5), and following the defect density Equation (6): Carrier Mobility (μ) = (8/9) × J × (L 3 /(V a 2 ·ɛ 0 ·ɛ r )) N defect (Defect Density) = (2·ɛ 0 ·ɛ r ∙V FTL )/(q·L 2 ) where J is the current density and L is the thickness of the active layer (PBDB-T:PC 71 BM and ITIC) measured using a surface profiler (KLA-Tencor Alpha-step AS-500). The V a is the applied voltage in the SCLC region, ɛ 0 is the free-space permittivity constant of the vacuum (8.85 × 10 − 12 F/m), the relative permittivity (ɛ r ) of the PBDB-T:PC 71 BM and PBDB-T:ITIC were 3.56 and 3.78, respectively [ 26 ].…”