Patent Description:
The present disclosure relates to the technical field of thin film transistor, in particular to the structure and manufacturing method of an organic thin film transistor, a gas sensor and a related apparatus.

The Organic Thin Film Transistor (OTFT) has the advantages of being low-cost and environment friendly and can be easily mass-produced. The gas sensor is an essential element in industrial production and smart home. At present, sensor application has been proved to be a good destination for OTFT technology. When the gas to be detected enters the carrier migration interface of the OTFT, it can affect the interface between the organic active layer and insulating layer so as to affect the carrier migration velocity of the OTFT, resulting in the reduction of the OTFT carrier mobility, and the decrease degree of the carrier is related to the concentration of the gas, that is to say, when meeting the gas to be detected, the OTFT has the characteristic of having significant change in mobility (becoming worse). Hence, the OTFT device can be applied to the gas sensor to detect the gas concentration, and the OTFT can take advantage of its low-cost feature especially in the application of disposable gas sensors. However, due to the limitation of the OTFT structure, it is difficult for the gas to reach the carrier migration interface, which causes low sensitivity of the OTFT to detect the gas concentration, and a poor detection effect on gas concentration. Chinese patent <CIT> discloses a gas sensor based on a field effect transistor structure and a preparation method of the gas sensor based on the field effect transistor structure. The gas sensor based on the field effect transistor structure includes substrate layers, a gate insulating layer, an active layer, a source electrode and a drain electrode, where the gate insulating layer is connected with the active layer, the gate insulating layer and the active layer are arranged between the substrate layers, a gate electrode, the source electrode and the drain electrode are arranged on the substrate layers, the gate insulating layer is made of insulating materials with microstructures, and the insulating materials with the microstructures are oxides or insulating polymers. According to the gas sensor based on the field effect transistor structure and the preparation method of the gas sensor based on the field effect transistor structure, due to the fact that the microstructures are arranged on the insulating materials to prepare the gate insulating layer, when gas is fed into the gate insulating layer with the microstructures, the capacitance of the gate insulating layer changes, changes of performance of a field effect transistor are caused, and the purpose of gas detection is achieved. The gas sensor based on the field effect transistor structure is wide in range of detection, and detection of various gases can be achieved. The obtained gas sensor is small in size, the size and cost of a detection device can be reduced, and the gas sensor based on the field effect transistor structure and the preparation method of the gas sensor based on the field effect transistor structure have good application prospect.

The present disclosure discloses in the Embodiments the structure of an organic thin film transistor, including:.

Optionally, the gap in the organic thin film transistor structure provided in the embodiments of the present disclosure passes through the gate insulating layer in a thickness direction of the gate insulating layer.

Optionally, in the organic thin film transistor structure provided in the embodiments of the present disclosure, spaces between any two adjacent strip gaps are same.

Optionally, in the organic thin film transistor structure provided in the embodiments of the present disclosure, the gate insulating layer further includes a plurality of sub-insulating layers separated by the strip gaps; spaces between any two adjacent sub-insulating layers are same.

Optionally, in the organic thin film transistor structure provided in the embodiments of the present disclosure, a material of the organic active layer is a donor-acceptor conjugated polymer PBIBDF-BT.

Optionally, in the organic thin film transistor structure provided in the embodiments of the present disclosure, a material of the gate insulating layer includes silicon nitride.

Optionally, in the organic thin film transistor structure provided in the embodiments of the present disclosure, the gate insulating layer is on the gate electrode, the organic active layer is on the gate insulating layer, and the source-drain electrode is on the organic active layer.

On the other hand, the present disclosure further provides in the embodiments a gas sensor, including the above described organic thin film transistor structure.

On the other hand, the present disclosure further provides in the embodiments a display panel including an array substrate, and a gas sensor arranged in a non-display area of the array substrate.

On the other hand, the present disclosure further provides in the embodiments a display device including the above-described display panel.

On the other hand, the present disclosure further provides in the embodiments a manufacturing method of the organic thin film transistor structure, including:.

Optionally, in the method provided in the embodiments of the present disclosure, the filling material includes poly (<NUM>, <NUM>-butylene adipate).

Optionally, in the method provided in the embodiments of the present disclosure, the cleaning fluid includes one or a combination of the following materials: acetone and ethyl acetate.

The present disclosure provides in the embodiments the structure and manufacturing method of an organic thin film transistor, a gas sensor and a related device to improve the sensitivity of the gas sensor for detecting the gas concentration and the detection effect on gas concentration.

The present disclosure provides in the embodiments the organic thin film transistor structure, as shown in <FIG>, including:.

The gap <NUM> arranged in contact with the organic active layer <NUM> and configured to accommodate the gas to be detected is set in the organic thin film transistor structure disclosed in the embodiments of the present disclosure. When the organic thin film transistor structure is used to detect the gas concentration, the gas to be detected can enter the interior of the organic thin film transistor structure through the gap <NUM> and the contact area between the gas to be detected and the organic active layer <NUM> is increased, thus the contact area between the gas to be detected and a carrier migration interface is increased. Accordingly, the sensitivity of the organic thin film transistor structure to detect the concentration of the gas to be detected and the detection effect on gas concentration are improved.

In the organic thin film transistor structure disclosed in the Embodiments of the present disclosure, as shown in <FIG>, the gap <NUM> passes through the gate insulating layer <NUM> in the thickness direction of the gate insulating layer <NUM> so as to increase as much as possible the space for accommodating the gas to be detected, which is helpful for the sufficient contact between the gas to be detected and the organic active layer <NUM>, thus the contact area between the gas to be detected and the carrier migration interface is increased. Accordingly, the sensitivity of the organic thin film transistor structure to detect the concentration of the gas to be detected and the detection effect on gas concentration are improved.

According to the claimed invention, in the organic thin film transistor structure disclosed in the Embodiments of the present disclosure, as shown in <FIG>, the gap <NUM> includes a plurality of strip gaps <NUM> extending substantially in the same direction.

The strip gaps <NUM> overlap mutually with the organic active layer <NUM> in the thickness direction of the organic active layer <NUM>.

The plurality of strip gaps <NUM> in mutual contact with the organic active layer <NUM> can ensure the sufficient contact between the gas to be detected and each area of the organic active layer <NUM>, thus the contact area between the gas to be detected and the carrier migration interface is increased. Accordingly, the sensitivity of the organic thin film transistor structure to detect the concentration of the gas to be detected and the detection effect on gas concentration are improved.

According to the claimed invention, in the organic thin film transistor structure disclosed in the embodiments of the present disclosure, as shown in <FIG>, the ends of the strip gaps <NUM> along the length direction (as shown in the dotted box in <FIG>) do not overlap with the organic active layer <NUM> in the thickness direction of the organic active layer <NUM>, that is, the ends of the strip gaps <NUM> along the length direction protrude from the organic active layer <NUM> so that the gas to be detected can enter from the ends of the strip gaps <NUM> along the length direction, which is helpful for the sufficient contact between the gas to be detected and the organic active layer <NUM>, thus the contact area between the gas to be detected and the carrier migration interface is increased. Accordingly, the sensitivity of the organic thin film transistor structure to detect the concentration of the gas to be detected and the detection effect on gas concentration are improved.

Optionally, in the organic thin film transistor structure provided in the embodiments of the present disclosure, the spaces between any two adjacent strip gaps <NUM> are equal. Thus, the strip gaps <NUM> are uniformly arranged in the gate insulating layer <NUM>. When the organic thin film transistor structure provided in the embodiments of the present disclosure is configured to detect the gas concentration, the gas to be detected can be evenly distributed on the carrier migration interface of the organic thin film transistor structure, thus making the gas concentration detection result more accurate.

Optionally, in the organic thin film transistor structure provided in the Embodiments of the present disclosure, as shown in <FIG>, the gate insulating layer <NUM> also includes a plurality of sub-insulating layers <NUM> separated by the strip gaps <NUM>; the spaces between any two adjacent sub-insulating layers <NUM> are same. Thus, it can ensure that the strip gaps <NUM> are uniformly arranged in the gate insulating layer <NUM>. When the organic thin film transistor structure provided in the embodiments of the present disclosure is configured to detect the gas concentration, the gas to be detected can be evenly distributed on the carrier migration interface of the organic thin film transistor structure, thus making the gas concentration detection result more accurate.

Optionally, in the organic thin film transistor structure provided in the embodiments of the present disclosure, the material of the organic active layer <NUM> can be selected from a donor-acceptor conjugated polymer (PBIBDF-BT).

Optionally, the molecular structure of the PBIBDF-BT is shown in <FIG>. The PBIBDF-BT is sensitive to the common gases including ammonia gas and sulfur dioxide that need to be detected in daily life. In addition, the PBIBDF-BT can also be used for the detection of ethanol, acetone, ether, n-hexane, methylbenzene, ethyl acetate, isopropanol, chloroform and other gases.

It should be noted that, for a certain kind of organic semiconductor material, it may only be sensitive to certain gases. When selecting the material for the organic active layer <NUM> of the organic thin film transistor structure, what needs to consider is what kind of gas needs to be detected when the material is applied in gas sensors, and then the material that is sensitive to that kind of gas is selected as the material for the organic active layer <NUM>.

Optionally, in the organic thin film transistor structure provided in the embodiments of the present disclosure, the material of the gate insulating layer <NUM> includes silicon nitride (SiNx).

Optionally, the organic thin film transistor structure provided in the embodiments of the present disclosure can be a bottom-gate type structure. Optionally, as shown in <FIG>, the gate insulating layer <NUM> is arranged to cover the gate electrode <NUM>, the organic active layer <NUM> is arranged to cover the gate insulating layer <NUM>, and the source-drain electrode <NUM> is arranged on the organic active layer <NUM>. Thus, in addition to contacting the organic active layer <NUM> through the gap <NUM>, the gas to be detected can also contact the organic active layer <NUM> through the upper surface of the organic active layer <NUM> so as to increase the contact area between the gas to be detected and the carrier migration interface. Accordingly, the sensitivity of the organic thin film transistor structure to detect the concentration of the gas to be detected and the detection effect on gas concentration are improved.

Alternatively, the organic thin film transistor structure provided in the Embodiments of the present disclosure can also be a top-gate type structure which is not be defined herein.

Based on the same invention concept, the embodiments of the present disclosure further provide a gas sensor including the above-described organic thin film transistor structure provided in the embodiments of the present disclosure.

Optionally, when the gas sensor provided in the embodiments of the present disclosure is configured to detect the gas concentration, the OTFT is in normal working condition before the gas to be detected enters the organic thin film transistor structure (OTFT), and the carrier mobility of the OTFT in this condition is a. When the gas to be detected enters the organic thin film transistor structure, the gas to be detected is in contact with the organic active layer <NUM> through the gap <NUM> so that the gaseous environment of the carrier migration interface changes, which is equivalent to that the carrier migration interface of the organic thin film transistor structure under the normal working condition is polluted by the gas to be detected, and the OTFT is in the abnormal working condition. The carrier mobility of the OTFT in the abnormal working condition is b. Compared with the OTFT in the normal working condition, the carrier mobility of the OTFT decreases, and the carrier mobility b is far less than a with the increase of the gas concentration. Therefore, the concentration of the gas to be detected in the environment can be judged according to the difference between b and a. The larger the difference between b and a is, the higher the gas concentration is; otherwise, the lower the gas concentration is.

For a certain kind of gas, the influence of gas concentration on the OTFT carrier mobility can be reflected as the influence of gas concentration on the OTFT transfer characteristic curve. When the gas concentration is different, the transfer characteristic curve is also different. Take the organic active layer of the OTFT, which is the PBIBDF-BT for example. As shown in <FIG>, seen from the far left of <FIG>, the OTFT transfer characteristic curves corresponding to different concentrations of the ammonia gas are shown from top to bottom. And the concentrations of the ammonia gas corresponding to the curves decrease from top to bottom: the uppermost curve corresponds to the OTFT transfer characteristic curve when the ammonia concentration percentage (parts per billion, ppm) is <NUM>, the bottom curve corresponds to the OTFT transfer characteristic curve when the ammonia ppm is <NUM>. When the driving voltage of the OTFT is constant and ppm is <NUM>, OTFT's Ion is the largest, and when ppm of the ammonia gas is <NUM>, OTFT's Ion is the smallest. The OTFT transfer characteristic curves for any kind of gas under different concentrations can be measured in advance; therefore, the relationship between the gas concentration and OTFT Ion under the same driving voltage can be fitted according to the pre-measured OTFT transfer characteristic curves of the gases with different concentrations. So when the OTFT is used to detect the gas concentration, the gas concentration can be determined according to the relationship between the gas concentration and OTFT Ion.

Based on the same disclosure concept, the present disclosure further provides in the embodiments a display panel including an array substrate, and the above-described gas sensor arranged in a non-display area of the array substrate.

Optionally, the above-described display panel provided in the embodiments of the present disclosure can be a liquid crystal display panel or an organic light-emitting diode display panel.

Optionally, in the above-described display panel provided in the Embodiments of the present disclosure, as shown in <FIG>, the array substrate includes: a base substrate <NUM>, a display structure <NUM> arranged on the base substrate <NUM> to realize the display function, a gas sensor <NUM> arranged on the base substrate <NUM>, an upper substrate <NUM> arranged above the display structure <NUM>, and an encapsulating material <NUM> for encapsulating the upper substrate <NUM> and the base substrate <NUM>.

When the display panel provided in the embodiments of the present disclosure is a liquid crystal display panel, it may be encapsulated with sealant; when the display panel provided in the embodiments of the present disclosure is an OLED display panel, it may be encapsulated with Frit. The material of the base substrate <NUM> and the upper substrate <NUM> can be, for example, glass. If the display panel is flexible liquid crystal display panel, the base substrate <NUM> and the upper substrate <NUM> can be selected from the flexible materials such as polyimide (PI), polyethylene terephthalate (PET) or polyethylene naphthalate (PEN).

It should be noted that the gas sensor can be set at any position of the display panel as long as it does not affect the display effect. For example, the position of the gas sensor can be planned and set in the non-display area of the display panel. In addition, the number of gas sensors can also be selected according to actual needs, and the present disclosure does not define it.

Based on the same invention concept, the present disclosure further provides in the embodiments a display device including the above-described display panel provided in the embodiments of the present disclosure.

For example, the display device provided in the embodiments of the present disclosure can be a display device such as a mobile phone, a television, and a tablet computer, etc..

The display device provided in the embodiments of the present disclosure also has the function of detecting the gas concentration since it has been set with the above-described gas sensor provided in the embodiments of the present disclosure. In daily life, the user may come into contact with some harmful gases. With the above-described display device provided in the embodiments of the present disclosure, the user can detect whether there is some kind of harmful gas in the current environment, and leave timely in the presence of harmful gas according to the test result to prevent harm to health caused by the harmful gas.

Corresponding to the organic thin film transistor structure provided in the embodiments of the present disclosure, the embodiments of the present disclosure further provide a manufacturing method of the organic thin film transistor structure, as shown in <FIG>, including:.

Optionally, in the preparation method of the above-described organic thin film transistor structure provided in the embodiments of the present disclosure, the gap configured to accommodate the gas to be detected is set in the gate insulating layer. When the organic thin film transistor structure prepared by this method is used to detect the gas concentration, the gas to be detected can enter the interior of the organic thin film transistor structure through the gap and the contact area between the gas to be detected and the carrier migration interface of the organic thin film transistor structure is increased, and the sensitivity of the organic thin film transistor structure to detect the concentration of the gas to be detected is improved,. Accordingly, the sensitivity to detect the concentration of the gas to be detected and the detection effect on gas concentration are improved.

It should be noted that, in the manufacturing method in the embodiments of the present disclosure, suitable filling materials and the corresponding cleaning fluid can be selected according to the material of each membrane layer of the organic thin film transistor structure so that the cleaning fluid in step S806 can only dissolve the filling material without affecting the other membrane layers of organic thin film transistor structure.

Optionally, in the preparation method provided in the embodiments of the present disclosure, the process is simple and easy to implement, and the cleaning fluid only dissolves the filling material without affecting the performance of the organic thin film transistor structure.

Optionally, in the above manufacturing method provided in the embodiments of the present disclosure, the filling material can be selected from polymer insulating materials, and the filling material includes poly(<NUM>,<NUM>-butylene adipate) (PBA), and the molecular structure formula of PBA is shown in <FIG>.

Optionally, in the method provided in the Embodiments of the present disclosure, the cleaning fluid includes one or a combination of the following materials: acetone and ethyl acetate.

The following embodiments are used to illustrate the manufacturing method of the above-described organic thin film transistor structure provided in the embodiments of the present disclosure: the material of the gate insulating layer is SiNx, the material of the organic active layer is PBIBDF-BT, the filling material is PBA, and the cleaning fluid is acetone.

As shown in <FIG>, the manufacturing method of the organic thin film transistor structure provided in the embodiments of the present disclosure includes the following steps:.

In the manufacturing method of the organic thin film transistor structure provided in the embodiments of the present disclosure, as shown in <FIG>, the material of the organic active layer of the organic thin film transistor structure is PBIBDF-BT, the filling material is PBA. When acetone is selected as a cleaning fluid to dissolve PBA, the molecular weight of PBIBDF-BT is much higher than that of PBA, and PBIBDF-BT could not be dissolved by acetone.

It should be noted that, steps S104 and S105 need to use PBIBDF-BT and PBA solution, wherein the molar mass of PBA is <NUM>/mol and the concentration of PBA can be within the range of <NUM>-<NUM>/ml; the molar mass of PBIBDF-BT is <NUM>,<NUM>/mol and the concentration of PBIBDF-BT can be within the range of <NUM>-<NUM>/ml. Both PBA and PBIBDF-BT can select polymers as the solvents, wherein polymers can be, for example, chloroform, chlorobenzene, dichlorobenzene, trichlorobenzene, and methylbenzene, etc..

In step S104, the ink-jet printing and spin-coating can also be used to fill the strip gaps with PBA.

In step S105, the drop-coating method can also be used to deposit PBIBDF-BT.

In addition, when depositing PBIBDF-BT in step S805, PBIBDF-BT does not completely cover the SiNx-PBA composite layer with some edges set aside. In this way, when the cleaning fluid is used to dissolve PBA in the subsequent step S06, the cleaning fluid could enter the SiNx-PBA composite layer through the edges set aside and dissolve PBA.

Corresponding to the display panel provided in the embodiments of the present disclosure, the present disclosure discloses in the embodiments a manufacturing method of the display panel. The display panel provided in the embodiments of the present disclosure includes a display structure and a gas sensor. Since the gas sensor also includes an OTFT, the preparation process of the OTFT can also be integrated with the TFT preparation process in the display structure. As shown in <FIG>, the preparation of the OTFT and display TFT includes the following steps:.

In the above-described preparation steps of the display panel provided in the embodiments of the present disclosure, the first is to set the organic active layer of the OTFT, and then the active layer of the display TFT is set. In actual production, the active layer of the display TFT can be set first and the organic active layer of the OTFT can be set then. When the material of the active layer of the display TFT is the same as that of the organic active layer of the OTFT, the active layers of the display TFT and OTFT can also be set at the same time.

In conclusion, the present disclosure provides in the embodiments the structure and manufacturing method of the organic thin film transistor, the gas sensor and the related device, and sets a gap arranged in contact with the organic active layer and configured to accommodate the gas to be detected in the organic thin film transistor structure. When the organic thin film transistor structure is used to detect the gas concentration, the gas to be detected can enter the interior of the organic thin film transistor structure through the gap and the contact area between the gas to be detected and the organic active layer is increased, thus the contact area between the gas to be detected and the carrier migration interface is also increased. Accordingly, the sensitivity of the organic thin film transistor structure to detect the concentration of the gas to be detected and the detection effect on gas concentration are improved.

Claim 1:
An organic thin film transistor structure, comprising:
a gate electrode (<NUM>);
an organic active layer (<NUM>) overlapping mutually with the gate electrode (<NUM>) in a thickness direction of the gate electrode (<NUM>);
a source-drain electrode (<NUM>) connected with the organic active layer (<NUM>); and
a gate insulating layer (<NUM>) which is between the gate electrode (<NUM>) and the organic active layer (<NUM>), wherein the gate insulating layer (<NUM>) comprises a gap (<NUM>) configured to accommodate a gas to be detected; wherein the gas to be detected accommodated in the gap (<NUM>) is in contact with the organic active layer (<NUM>);
wherein the gap (<NUM>) comprises a plurality of strip gaps (<NUM>) extending substantially in a same direction;
the strip gaps (<NUM>) overlap mutually with the organic active layer (<NUM>) in a thickness direction of the organic active layer (<NUM>);
characterised in that:
ends of the strip gaps (<NUM>) along a length direction protrude from the organic active layer (<NUM>); and
the organic active layer (<NUM>) does not completely cover the gate insulating layer (<NUM>).