Search

The Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) ferroelectric single crystals have been commercially available as important components in medical ultrasound transducers due to their excellent piezoelectric and electromechanical coupling performance. The variation in piezoelectric and dielectric properties of PMN-PT single crystals with ambient temperature is an important application indicator. In this work, the PMN-PT single crystals after direct current poling (DCP) and alternating current poling (ACP) were subjected to the cyclic thermal treatment process. The thermal cycling stability and microstructural changes in PMN-PT single crystals were investigated. The ACP single crystals exhibit a higher dielectric constant ε 33 T / ε 0 (6500–7600) and piezoelectric coefficient d33 (2100–2500 pC N−1) compared to the DCP single crystals (ε 33 T / ε 0 of 4100–5000, d33 of 1200–1300 pC N−1). Under thermal cycling at 60 °C, the DCP and ACP single crystals exhibit good thermal cycling stability after 150 cycles. Microstructural observations show that the domain structure of the DCP single crystals exhibits "staggered domain walls, inhomogeneous domain size, variety of domain structure," while the relatively homogeneous stripe-like domains were observed in the ACP single crystals. After thermal cycling, new fine striped domains appear in both the DCP and ACP single crystals due to the instability of rotated polarization, but the piezoelectric and dielectric properties are not greatly affected. This work provides an intensive understanding of the effects of thermal cycling on the domain structure, which is useful for applications. [ABSTRACT FROM AUTHOR]

Large-size Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) based ferroelectric single crystals have been grown successfully by the vertical Bridgman method for application in the field of high-end piezoelectric devices. The piezoelectric and dielectric performance uniformity of PMN-PT based ferroelectric crystals is a critical application requirement. Recently, alternating current poling (ACP) has attracted much attention due to its low cost and high efficiency in improving the piezoelectric properties of PMN-PT based crystals. Here, we report the comparison of the performance fluctuation of direct current poling (DCP) and ACP Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) ferroelectric single crystals grown in the [110] direction using the vertical Bridgman method. The fluctuation of piezoelectric coefficient d33, dielectric constant ɛT33/ɛ0, and dielectric loss tanδ was presented. We found that the average d33 and ɛT33/ɛ0 of ACP samples are 1290 and 1500 pC/N and 3890 and 4290 for two different wafers, which were 18% and 23%, 21% and 26% higher than DCP samples. The tanδ of ACP samples was much lower than that of DCP samples. The DCP and ACP samples exhibited the close data of the fluctuation ratios of d33 and ɛT33/ɛ0. The fluctuation ratios of d33 and ɛT33/ɛ0 for DCP and ACP samples are all less than 10%. This work offers a reference for practical ACP technique applications. [ABSTRACT FROM AUTHOR]

Phase matching is indispensable for high efficiency of second‐order nonlinear optical (NLO) crystals. Thousands of these crystals rely on birefringence phase matching, whereas only a few of them are quasi‐phase matching without the restriction of birefringence. Herein, using oriented seeds inch‐sized LiNH4SO4 (LAS) single crystals are successfully grown. LAS is NLO‐active with a very short deep‐UV absorption edge of 171 nm and high laser damage threshold up to 1.47 GW cm−2 at 1064 nm, 10 ns, but its birefringence is merely 0.0078@532 nm, which is too small to realize birefringence phase matching in deep‐UV region. Fortunately, P−E hysteresis loop, variable‐temperature NLO tests, and ferroelectric domain observations confirm that LAS is ferroelectric. Furthermore, LAS exhibits small refractive index dispersion resulting in a relatively long periodic length of 1.4 µm and its single domain structure can be easily obtained by electrical poling. These attributes make LAS a scarce NLO candidate for deep‐UV quasi‐phase matching. This work highlights the longly overlooked potential of sulfates and provides new opportunities for deep‐UV NLO materials. [ABSTRACT FROM AUTHOR]

Piezoelectric and dielectric properties of [001] and [110]-oriented tetragonal Pb(In1/2Nb1/2)-Pb(Mg1/3Nb2/3)-PbTiO3 (PIN-PMN-PT) single crystals (SCs) after alternate current poling (ACP) were investigated. Compared with direct current poling (DCP), the piezoelectric and dielectric properties of [001]-oriented samples have no improvement, while the piezoelectric coefficient d33 and free dielectric constant ε 33 T / ε 0 of [110]-oriented samples increase by 32% and 26%, respectively. The domain was observed on (001) and (1 1 ¯ 0) faces of [110]-oriented samples. The enhancement of the piezoelectric performance is attributed to the high density of domain wall, increase of distorted regions between 90° domains, and monoclinic phase. Compared with DCP, both intrinsic and extrinsic contributions enhance after ACP though the Rayleigh analysis. This work indicates that ACP is an effective way to enhance piezoelectric properties of non-polar axis oriented relaxor-PT ferroelectric SCs. [ABSTRACT FROM AUTHOR]

Alternating current poling (ACP) is an effective method to improve the piezoelectric performance of relaxor-PbTiO3 (PT) ferroelectric single crystal. 0.72Pb(Mg1/3Nb2/3)O3-0.28PbTiO3 (PMN-PT) single crystals have been used to fabricate piezoelectric transducers for medical imaging. Up to date, there are no reports about the full matrix material constants of PMN-0.28PT single crystals poled by ACP. Here, we report the complete sets of elastic, dielectric, and piezoelectric properties of [001]-poled PMN-0.28PT single crystals by direct current poling (DCP) and ACP through the resonance method. The results show that [001]-poled rhombohedral PMN-0.28PT single crystals exhibit the enhancement of longitudinal and transverse piezoelectric properties (${d}_{33} \sim 2000$ pC/N, ${d}_{31} \sim -1010$ pC/N) after ACP. Compared with DCP samples (${d}_{33} \sim 1660$ pC/N, ${d}_{31} \sim -780$ pC/N), the values of ${d}_{33}$ and ${d}_{31}$ increase 20% and 29%, respectively. While the ${d}_{15}$ value decrease from 110 pC/N for DCP sample to 90 pC/N for ACP sample, showing the decrease in transverse shear piezoelectric properties. In addition, the elastic stiffness coefficients ${c}_{11}$ , ${c}_{12}$ , ${c}_{13}$ , the elastic compliance coefficients ${s}_{11}$ , ${s}_{12}$ , and the dielectric constants $\varepsilon _{11}$ , $\varepsilon _{33}$ have great change compared with DCP and ACP samples. This variation of the property matrices provides a reference for high-performance piezoelectric device design. [ABSTRACT FROM AUTHOR]

High-performance piezoelectric materials for actuators, sensors, and transducers are urgently required. It would be ideal to always have high piezoelectric performance and high ferroelectric-ferroelectric phase transition temperature, but we have only one in most cases. Pb(In0.5Nb0.5)O3–PbTiO3 (PIN-PT) crystals have a high rhombohedral-tetragonal phase transition temperature (TRT), but the piezoelectric performance is not very satisfactory. Here, Nd-doped PIN-0.33PT single crystals were grown, where the enhanced piezoelectric d33 and electromechanical coupling coefficient k33 are 2100 pC/N and 91%, which are 80% and 5.8% higher than those for virgin PIN-0.33PT single crystals (1160 pC/N and 86%) and are superior to that of other compositions of PIN-PT crystals. Piezo-response force microscopy was adopted to study the domain structure, and the domain size was found to decrease after Nd doping, which contributes to the enhanced piezoelectric performance. This study offers a good paradigm for enhancing the piezoelectric performance of high Curie temperature ferroelectric single crystals. [ABSTRACT FROM AUTHOR]

Orientation dependence of electrical properties and domain configurations of 8 mol% Mn‐doped rhombohedral PIN‐PT (0.68Pb(In0.5Nb0.5)O3–0.32Pb(Ti0.92Mn0.08)O3) rhombohedral single crystals were investigated with an emphasis on studying the variations of coercive field (EC), internal field (Ei) on domain patterns. Our results showed that for both [001] and [110]‐oriented samples, the coercive field and internal field decreased with temperature (T) increasing in rhombohedral phase, and a peak appeared above rhombohedral‐tetragonal phase transition temperature (TRT). The abnormal peaks between TRT and Curie temperature on EC‐T and Ei‐T plots are explained by taking into consideration the ferroelectric phase transition and variation of defect polarization, which provides assistant comprehension on the dynamic of defect dipoles during phase transition at high temperature. Bubble‐ and ribbon‐like domain patterns were observed in (001)‐ and (110)‐plane, respectively, and smaller value of short‐length correlation radius in (001)‐ plane indicates less aggregation of polar nanoregions in this crystallographic plane than that in (110)‐plane. [ABSTRACT FROM AUTHOR]

In this report, phototransistors based on rubrene single crystals have been fabricated using octyltrichlorosilane (OTS) treated SiO2 as a substrate and memory effect has been observed and studied. Memory writing realized by the combined stimulation of applied gate voltage and light illumination was observed to be strongly dependent on the applied gate voltage. When the applied gate voltage, Vg = 100 V, only 500 ms writing time was found to be sufficient to achieve the memory window of 25 V. Long retention time of over 10 000 s as well as stable writing-reading-erasing-circle were also observed in the rubrene single crystal based phototransistor device. Even at high temperature of 100 °C, the device demonstrated stable memory effect. Thus we attributed the excellent memory effect to the deep electron traps. To clarify further the origin of persistent photocurrent, strongly hydrophobic fluorinated polyimide (FPI) was used as a dielectric layer to exclude the hydroxyl groups at the semiconductor/insulator interface. Compared to the OTS treated SiO2 based device, the photocurrent was saturated in a shorter time in FPI based counterpart, regardless of the light intensity and persistent photoconductivity was also observed. X-ray photoelectron spectroscopy analysis of rubrene single crystal revealed the existence of characteristic oxidation states, both in the high resolution C 1s and O 1s spectra, which behave as electron traps. In conclusion, we attribute the photo memory effect in rubrene single crystal based device to the oxygen related defects as well as to the hydroxyl groups at the dielectric/single crystal interface. [ABSTRACT FROM AUTHOR]

The phase diagram of the Pb(Lu0.5Nb0.5)O3-PbTiO3 (PLN-PT) binary system was previously reported based on XRD and dielectric measurements results. Unusually, the Curie temperature of PLN-PT with low PT obtained from the phase diagram is much lower than that of PLN and PT end members, which is different from others, such as PZT. Therefore, the complex structure of PLN-PT with low PT is desired to be studied. In this work, PLN-PT single crystals with low PT were grown for the study of their super-lattice structure and phase evolution. The super-lattice reflections were identified by X-ray diffraction. Domains and their evolution by heating from room temperature to 150 °C were observed under a polarized light microscope. The phase transition from the ferroelectric phase to the paraelectric phase was determined by dielectric spectra and polarized light microscopy. A precursor/intermediate phase exhibiting pinched hysteresis loops was displayed above the Curie temperature, which originates from some polar region embedded in the non-polar matrix. The coexistence of the ferroelectric and antiferroelectric domains leads to peculiarities of the phase transitions, such as a lower Curie temperature compared with PLN and PT. The studies of the phase evolution of PLN-PT with low PT single crystal is a supplementary amendment of the PLN-PT phase diagram as previously reported. [ABSTRACT FROM AUTHOR]

In ferroelectric materials, significant piezoelectric response only occurs after poling by an external electric field applied along a certain crystallographic direction, and the piezoelectric effect generally disappears upon heating to the Curie temperature (T C ) where the poled state vanishes. This thermally induced depoling often restricts the temperature range for the applications of piezoelectric devices. It has been a challenge to develop materials that exhibit high piezoelectric performance that is not affected by electric poling, nor thermal depoling. Here we report an unusual piezoelectric effect found in Pb(Mg 1/3 Nb 2/3 )O 3 -PbSnO 3 -PbTiO 3 ternary ferroelectric crystals which exhibit a relatively high piezoelectricity (with the piezoelectric coefficient d 33 = 1350–1400 pC/N) without undergoing any poling process. Moreover, this high piezoelectric performance is retained after repeated thermal annealing at temperatures above T C , showing a piezoelectric memory effect. This uncommon piezoelectric effect is explained by a self-polarization mechanism based on the defect-dipoles formed in the crystals due to the presence of mixed valence states of Sn 2+/4+ . The defect-dipoles generate internal bias electric fields which, in turn, provide the stabilizing and restoring forces leading to preferred orientation states and the retention of spontaneous polarization. This mechanism offers a new perspective for designing novel piezoelectric materials with high performance and a wide temperature range of operation. [ABSTRACT FROM AUTHOR]

A multiferroic crystal of 0.25BiFeO 3 -0.59Pb(Fe 1/2 Nb 1/2 )O 3 -0.16PbTiO 3 with dimension of 7×7×5 mm 3 was firstly grown by a top-seeded solution growth (TSSG) technique. The structure, dielectric, ferroelectirc and magnetic properties of the grown crystal were characterized. The crystal shows a pure tetragonal perovskite structure with space group of P4mm (99). The Curie temperature T C is close to 417 K with a low dielectric constant at room temperature ( ɛ RT ~422 at 1000 Hz). The hysteresis loop shows that the remanent polarization P r and the coercive field E C in [001]-oriented crystal are 26.3 μC/cm 2 and 8.6 kV/cm, respectively. The piezoelectric coefficient d 33 reaches 345 pC/N in [001]-oriented sample, much higher than the other BiFeO 3 -based crystals. The magnetic hysteretic loops at 2 K and temperature dependence of magnetization show the crystal material is weak antiferromagnetic with Neel Temperature T N ~125 K. [ABSTRACT FROM AUTHOR]

Within the morphotropic phase boundary region, 0.39PSN-0.13PMN-0.48PT crystals exhibit excellent properties. The dielectric response of poled 〈001〉-oriented 0.39PSN-0.13PMN-0.48PT crystal plates displays non-relaxor behavior with Curie and depolarization temperatures of about 230 °C and 199 °C, respectively, exhibiting high temperature stability of the ferroelectric phase. The saturated polarization-electric field loop of the same plate manifests the switching of domains, with the coercive field of approximately 5.6 kV/cm, indicating stable piezoelectric properties. The out of plane and in plane domain configurations exhibit obvious domain walls. The typical butterfly strain-electric field curve presents a large peak to peak strain value of about 0.59%. The piezoelectric constant is calculated to be about 1670 pC/N from the unipolar stain-electric field curve. [ABSTRACT FROM AUTHOR]

High quality La 0.011 Pb 0.984 (Lu 1/2 Nb 1/2 )O 3 (La-PLN) antiferroelectric (AFE) single crystal was successfully obtained by a top-seed solution growth technique. The crystal structure adopts an orthorhombic phase and two sets of superlattice reflections due to B-site ordering and anti-parallel cation displacement are observed clearly and distinguished by the X-ray diffraction patterns (XRD). The Curie temperature T C is near 221 °C with a low dielectric constant (about 371). The energy storage density decreases along with the temperature increasing and the maximum energy storage density is up to 5.03 J/cm 3 at 25 °C. The results indicate that the La-PLN single crystal is a promising candidate for the AFE energy storage application. [ABSTRACT FROM AUTHOR]

A cyanostilbene-based derivative with aggregation induced-emission was obtained, which exhibited multi-luminescent intensity under external stimuli. The as-prepared crystals of the desired dye showed a rather faint luminescence. Upon heating, its fluorescence could be turned on with the quantum yields of 13.3%. The quantum yields of the melted and solidified powders were further increased to 28.6%. Powder X-ray diffractometry, fluorescence spectroscopy, fluorescence lifetime experiments and single crystal XRD analyses were applied to investigate the changes of molecular packing modes. Such a transformation of fluorescence “dark”–“bright”, easily distinguished by naked eye, was related to the phase transition. The planar cyanostilbene with H-type packing and multiple mutable interactions may be the essential factor for the multi-luminescent intensity properties. [ABSTRACT FROM AUTHOR]

Abstract: The (1− x)Pb(In1/2Nb1/2)O3–xPbTiO3 (x =34.5%) ferroelectric single crystals with the dimensions of 21×21×8mm3 have been successfully grown by the top-seed solution growth method for the first time. The Curie temperature TC , rhombohedral-tetragonal phase transition temperature TRT , piezoelectric coefficient d 33, electromechanical coupling coefficient k 33, coercive field Ec and remanent polarization Pr are found to be 290°C, 150°C, 1720pC/N, 88%, 9.0kV/cm, 30μC/cm2, respectively, exhibiting good comprehensive piezoelectric properties. The heat treatment experiments reveal the good thermal stability of the grown crystal, making it a promising candidate in high temperature and high power application. [Copyright &y& Elsevier]

Reversible crystal-to-amorphous-to-crystal phase transition accompanied by changes in magnetic and NLO properties was first observed in a rigid non-porous spongelike MOF material. The crystal phase exhibits a high magnetocaloric effect, while the amorphous phase has potential application as a magnetic DMF sensor. [ABSTRACT FROM AUTHOR]

A ternary piezo-/ferroelectric crystal of Pb(Ho 1/2 Nb 1/2 )O 3 -Pb(Mg 1/3 Nb 2/3 )O 3 -PbTiO 3 with dimensions of 24×24×15 mm 3 has been grown by the top-seeded solution growth (TSSG) method for the first time. The structural and the di-/piezo-/ferro-electric properties of the grown crystal were characterized. The piezoelectric coefficient d 33 reaches 3297 pC/N in [0 0 1]-oriented sample, much higher than the other previously reported ternary crystals. The Curie temperature T C and the rhombohedral-tetragonal phase transition temperature T RT reaches 140 °C and 76 °C, respectively. The dielectric constant ε΄, dielectric loss tangent tanδ, longitudinal electromechanical coupling coefficient k 33 , remnant polarization P r and coercive field E c at room temperature for [0 0 1]-oriented crystals were found to be 10390, 0.068, 92%, 24.5µC/cm 2 and 3.22 kV/cm, respectively. These results show that the Pb(Ho 1/2 Nb 1/2 )O 3 -Pb(Mg 1/3 Nb 2/3 )O 3 -PbTiO 3 crystal is a promising candidate for the application in electromechanical transducers field. [ABSTRACT FROM AUTHOR]

The easily cracking behavior of relaxor-PbTiO 3 based ferroelectric crystals limit their application. The average thermal expansion coefficients of PMN-PT and PIN-PMN-PT single crystals are 7.77–8.21 × 10−6 K−1 and 6.59–7.79 × 10−6 K−1 between 20–600 °C. The compression of the crystal by the platinum crucible and the abnormal thermal expansion behavior around phase transition temperature during the cooling process are the main cause of crystal cracking. [Display omitted] • The average thermal expansion coefficients of PMN-PT and PIN-PMN-PT single crystals are 7.77–8.21 × 10–6 K−1 and 6.59–6.79 × 10–6 K−1 between 20–600 °C. • The compression of the crystal by the platinum crucible and the abnormal thermal expansion behavior around phase transition temperature during the cooling process are the main cause of crystal cracking. Large-size Pb(Mg 1/3 Nb 2/3)O 3 -PbTiO 3 (PMN-PT) and Pb(In 1/2 Nb 1/2)O 3 -Pb(Mg 1/3 Nb 2/3)O 3 -PbTiO 3 (PIN-PMN-PT) single crystals have been successfully produced. Nevertheless, the susceptibility of these crystals to cracking substantially hampers their application. This study investigates the thermal expansion characteristics of PMN-PT and PIN-PMN-PT crystals oriented along the 〈1 0 0〉, 〈1 1 0〉, and 〈1 1 1〉 directions, revealing no significant anisotropy. The average thermal expansion coefficients for the PMN-PT and PIN-PMN-PT crystals range from 7.77 to 8.21 × 10−6 K−1 and from 6.59 to 6.79 × 10−6 K−1, respectively, within the temperature range of 20 to 600 °C. Interestingly, the PMN-PT and PIN-PMN-PT crystals demonstrate unusual thermal expansion behavior around the phase transition temperature. The magnitudes of their thermal expansion coefficients are comparable to those of certain commercial crystals but are lower than that of platinum. The main causes inferred for crystal cracking include the pressure exerted by the platinum crucible and the abnormal thermal expansion behavior around the phase transition temperature. [ABSTRACT FROM AUTHOR]

Yttrium iron garnet (YIG) crystals are the primary candidate for non-reciprocal device. With the miniaturization and integration of optical communication devices, the modified YIG crystals with excellent comprehensive performances are highly desired. To explore the possible mechanism of rare earth ions doping on Faraday effect, holmium oxide-doped YIG (Ho 0.6 Y 2.4 Fe 5 O 12 , abbreviated as HYIG) crystal was grown by molten salt method. Its structure, optical transparency, magnetic, magneto-optical properties and oxygen atmosphere annealing processes were first investigated systematically. The HYIG crystal wafers annealed at 800 °C for 2 h can achieve the large Faraday rotation angle (186 deg/cm at 1310 nm; 148 deg/cm at 1550 nm) and good optical transparency (73.64 % at 1310 nm; 74.83 % at 1550 nm), which is increased by approximately 10 % compared to the unannealed sample. This result may provide a new insight into the investigation of rare earth doped YIG crystals and their atmosphere annealing processes. [Display omitted] • Centimeter-size HYIG crystal with Ho3+ doping was grown by the TSSG method. • The content of oxygen vacancy and Fe2+ ion decreased after annealing. • The transmittance and Faraday rotation angle are increased by about 10 % after annealing at 800 °C. [ABSTRACT FROM AUTHOR]

The regular domain structure is beneficial to the enhancement of piezoelectric properties of relaxor-PbTiO 3 ferroelectric crystals after alternating current poling (ACP). However, one shortcoming of ACP is that there are some non-rotational domains. Another is that ACP has no effect on polar axis-oriented crystals. Therefore, ACP is not very satisfactory for the morphotropic phase boundary (MPB) composition. Here, we demonstrate a pulse poling (PP) method that can lead to substantially increase the piezoelectric coefficient d 33 of MPB region Pb(In 1/2 Nb 1/2)O 3 -PbTiO 3 (PIN-PT) single crystals. The d 33 and free dielectric permittivity εT 33 /ε 0 of ACP [001] c -oriented 0.65PIN-0.35PT single crystals are 1490 pC/N and 3360, which are smaller than DCP sample (1640 pC/N and 3620). The d 33 and εT 33 /ε 0 after PP method are 2400 pC/N and 5390, having 61% and 60% improvement compared with ACP method. This work presents a new domain engineering method for achieving high piezoelectricity of these MPB region ferroelectric crystals. A new poling method called pulse poling was proposed for improving the piezoelectric properties of MPB region relaxor-PT single crystals. The d 33 and εT 33 /ε 0 of 0.65PIN-0.35PT single crystals after PP method are 2400 pC/N and 5390, having 61%, 60% and 46% and 49% higher than that of ACP and DCP samples [Display omitted]. [ABSTRACT FROM AUTHOR]

• Ternary PIN-PMN-PT crystals were successfully grown in 〈0 0 1〉 direction. • The PT content increased from 31 mol%to 35 mol% along the growth direction. • The relative difference of d 33 was reduced from ±31% to ±15% after modified the poling electric field. • The 80% of the crystals boule maintain d 33 of 1700–1900 pC/N and ε 33 T / ε 0 of 4500–5000. As a typical representative of the second generation of relaxor-PbTiO 3 (PT) ferroelectric single crystals, Pb(In 1/2 Nb 1/2)O 3 -Pb(Mg 1/3 Nb 2/3)O 3 -PbTiO 3 (PIN-PMN-PT) single crystals exhibit an improved thermal stability of piezoelectric properties compared with PMN-PT single crystals. The high quality and large-size PIN-PMN-PT single crystals are required for transducers. Composition segregation inevitably exists in relaxor-PT ferroelectric crystals grown by the vertical Bridgman method, resulting in poor uniformity of piezoelectric properties. The single crystal boule grown in 〈0 0 1〉 direction have the best composition uniformity. In this work, the composition uniformity of PIN-PMN-PT single crystals grown in 〈0 0 1〉 direction was investigated. The PT content varies from 31 mol% to 35 mol% from the bottom to the top of crystal boule. The T R/M−T decreases gradually from 113 °C to 73 °C and T C increases from 155 °C to 184 °C respectively. Optimizing the poling condition, the dielectric and piezoelectric properties of 80% of the single crystal boule can keep consistent. The free dielectric constant ε 33 T / ε 0 and piezoelectric coefficient d 33 are 4500–5000 and 1700–1900 pC/N, respectively, showing the improvement of the utilization of crystal boule. [ABSTRACT FROM AUTHOR]

In this report, 2,7-bis(4-methoxyphenyl)[1]benzothieno [3,2-b][1]benzothiophene. (DBOP-BTBT) organic single crystal field-effect transistors (OSCFETs) based on octyltrichlorosilane (OTS) and hexamethyldisilazane (HMDS) treated substrates have been systematically investigated. During all three consecutive scans of all transistors with different orientation in a-b plane, transistors modified with HMDS exhibit negligible hysteresis, while those modified with OTS show large hysteresis. Meanwhile, a high mobility up to 12.9 cm2 V-1 s-1 is obtianed for HMDS devices, compared to 7.7 cm2V-1 s-1 for devices modified with OTS. The hysteresis difference can be explained by the different trap densities between forward scan and reverse scan. Furthermore, the discrepancy in mobilities of forward and reverse scans is interpreted using a scattering model. Finally, after comparing the surface energies HMDS and OTS treated substrates, we attribute the performance difference between HMDS and OTS modified devices to the difference in intermolecular interaction between the SAMs and water. The work here indicates the importance of fine selection of SAMs for OSCFETs. Image 1 • Compared with OTS devices, HMDS devices exhibit little hysteresis and higher mobility in a-b plane. • Hysteresis is elucidated by the discrepancy of hole trap density at the interface between forward and reverse scans. • The discrepancy of mobility in consecutive scanning was found and elucidated by "carrier scattering model". • Performances difference between HMDS and OTS devices are found to derive from different interaction between SAMs and water. [ABSTRACT FROM AUTHOR]