igzo tft display pricelist

You made it to the end … or you skipped straight here in the hopes of getting a score and a definitive recommendation on whether to buy the Monoprice 27″ Dark Matter IGZO display.  Well, the journey here contains all the details, this is merely a summary of what we saw along the way.

The price Monoprice is charging for this monitor is somewhat higher than your average 27″ 1440p display which features Adaptive Sync and a high refresh rate.  If those are your only needs then perhaps it is not worth the extra money to upgrade from an IPS or VA panel to an IGZO-TFT display.  Then again, most of those displays top out around 165Hz at most, whereas this one can hit 180Hz, with the proper hardware driving it, if that is worth an extra $100 or so to you.

If those features above are just part of what you need however, suddenly this Dark Matter becomes a much better deal.  IGZO is rare these days outside of OLED panels and you can easily pay more than twice that for a display with similar specifications.  The visual quality of the display is noticeably superior to the VA panel I usually use, the contrast and overall responsiveness is unquestionable.  There is also the fact that even with this pixel density and brightness, it sips energy at 37 watts under full power, since the majority of display seem to post their power usage at 200 nits not the full 400 nits they are capable of, not to mention this displays lack of a backlight.

The stand might not be sufficient for your needs, but the extra price for a proper VESA arm is not much to ask and provides better adjustment capabilities than even the fancy stands packaged with other gaming displays.  It does add a bit of cost to the $350 you already spent, but will still be far less than you’d spend on other IGZO displays.

For usage mixed between business and pleasure, or for those that take the time to check out the environments in your game, it is honestly hard to beat the Monoprice Dark Matter IGZO 27″ display.  This may change as more companies adopt IGZO-TFT, but for now Monoprice is your best bet.

*Power usage- This monitor really does use 10w or less as described/support confirmed. It won"t drain the battery as fast as others! Partially this is probably from the 1080p panel. Personally, if you are looking for an actual PORTABLE monitor or for mainly productivity work, you WANT this resolution. 4K isn"t always better, or needed, and it seriously drains power. 1080p is a plus for real portable users and when I had 4K screens, I ended up changing the resolution lower anyway so it was truly a waste. With the 1080p on this monitor, it"s plug and play, no display scaling, no power drain. Unless you"re doing really specific display work, this is more than sufficient and on a screen this "small" (vs a full 27" home monitor, for example), the FHD QLED screen looks perfectly crisp and acceptable.

If you pay any attention to digital devices, news about improved display resolution is inescapable. Everyone wants higher-resolution displays; even people who think they don’t care about high resolution find it essential once they start using it. HDTV has become the norm, and consumers are increasingly adopting Ultra HD, or 4K TVs, with four times the resolution. Meanwhile, portable devices—tablets and phones—that equal or exceed the resolution of HDTV are increasingly available for demanding consumers.

Consumers demand a lot of other things, too, especially in portable devices. They want long battery life, snappy performance, and they want their displays to be gorgeous, with great touch sensitivity and ease of use.

Back in the office, the demand is just as great. Ever-larger monitors, with ever-higher resolution and touch-sensitive displays are increasing productivity in a number of applications.

Delivering high-resolution, low-power displays with bright, true colors is no easy task. While liquid crystal (LCD) displays have become the norm, the science inside the display is changing dramatically. Sharp Corporation has been at the forefront of LCD development since the earliest days, and has invested heavily in advancing the state of the art. The challenges of delivering high resolution and low power consumption have pushed traditional silicon technology to the limit. Sharp has pioneered a new display technology, called IGZO, which solves existing problems and opens the door to even greater display performance.

IGZO brings together Indium, Gallium, Zinc and Oxygen to form a metallic compound. IGZO has been known for its semiconductor properties for years, but Sharp engineers, along with Semiconductor Energy Laboratory, Co., Ltd., have developed a crystalline form that maximizes its benefits. Thin-film transistors are at the heart of every LCD, and IGZO improves the performance of LCD panels in three significant ways: lower power consumption, higher resolution and special benefits for touch-sensitive displays.

The science behind IGZO is revolutionary because it improves on silicon in several important ways. The thin-film transistors that power LCD displays act as switches, delivering an electrical charge to each liquid-crystal molecule that flips it from opaque to transparent. IGZO transistors have higher electron mobility than amorphous silicon transistors. They also have much lower leakage characteristics than the two dominant silicon transistors, amorphous silicon and low-temperature polysilicon. IGZO TFTs are smaller, so displays can have higher resolution with no loss in light transmission.

Electron mobility is important because electrons need to move quickly and in quantity through a material in order to switch fast for best display performance. Semiconductor materials vary greatly in the speed and the number of electrons available when the device switches on. As their name implies, semiconductor materials have to sometimes conduct electricity and other times act as an insulator. In an ideal world, they would be perfect conductors and perfect insulators, but electron leakage is a significant factor in many display technologies. It causes slower, poorer performance and also increases power consumption. IGZO is much closer to an ideal material than silicon, with far lower electron leakage.

These high-mobility, low-leakage transistors are smaller than conventional amorphous silicon-based TFTs, which means that each transistor takes up less area in each red, blue, or green subpixel. More light from the backlight gets through since less is blocked by the transistor. As a result, the display can be brighter overall or the light source doesn’t need to be as bright to achieve the same intensity to your eye as a conventional silicon-based display. The backlight thus requires less power. Combined with the lower power of the IGZO TFTs, the battery life benefits are obvious for portable devices.

Beyond the obvious advantage of greater efficiency and lower power consumption, the superior semiconductor properties of IGZO have another important benefit: low noise. An LCD has millions of transistors, all switching on and off rapidly. This switching causes electrical noise, but lower power equals less noise.

As shown in the chart below, the constant switching of conventional TFT transistors generates large amounts of electrical noise. This noise can mask the pulse generated when the screen is touched, or make it harder to distinguish. In contrast, IGZO-driven displays can hold a static image longer on the screen without switching because of their low leakage characteristics. There is no switching and no electrical noise, as shown in the diagram on the right. During these pauses touch sensitivity is maximized.

Low noise is vital to touch-sensitive displays. The more noise it generates, the more it interferes with the invisibly fine mesh of conductors that sense the position of your finger or a stylus. When the LCD is quiet, engineers can turn up the sensitivity of the position-sensing electronics, making it more accurate, more responsive. On high-resolution displays, the IGZO panel allows use of a fine-tipped stylus as well as a finger for remarkably precise pointing and drawing.

Beyond the difficult scientific research and engineering, Sharp has achieved large-scale manufacture of IGZO panels, effectively moving the technology from the laboratory into products for consumers. Advanced smartphones, tablet computers and monitors with IGZO LCDs are available today, and they incorporate all of the benefits mentioned above.

But LCDs are just the first type of display to benefit from IGZO. Many other kinds of displays can use the technology, with many of the same benefits. Sharp has demonstrated displays based on MEMS (Micro Electro Mechanical Systems), where IGZO transistors drive microscopically small components that actually move, such as arrays of shutters. Jointly developed with Pixtronix Inc., a subsidiary of Qualcomm Incorporated, these displays will address different market needs, such as ultra-low power, vivid color and wide temperature range.

IGZO also shows great promise as the foundation for a new class of sensors, which will be useful in the biomedical field. In every case, the limitations of existing technologies are being swept aside to create products that will make our lives more productive, more creative, more convenient and healthier. Sharp, with IGZO, is helping to invent the future, today.

a-IGZO-based TFT fabricated via CL-ES process shows the same mask number to that of BCE process (Fig. 1). Compared with a-IGZO-based TFT with BCE structure, a-IGZO-based TFT with CL-ES structure shows two advantages: (1) a-IGZO-based backplane produced using CL-ES process deposits gate insulator, a-IGZO nano-layer, and ES nano-layer sequentially, then forms a ESL nano-mask through dry-etch method. This newly formed ESL nano-mask with 100 nm can prevent the exposure of a-IGZO nano-film to etchant, stripper, or photoresist. Therefore, the contamination at inter-layer interfaces is effectively prevented [25]. (2) At the same time, a-IGZO nano-film is not protected by ES layer but bombarded by CF4 plasma during the ESL nano-mask formation, thus becomes a conductor. This naturally forms the Ohmic contact between S/D electrode of following process and a-IGZO semiconductor. For another part, a simultaneous etching of S/D and a-IGZO nano-layer can be one overlay allowance of ESL-(a-IGZO+S/D metallization) layer, which could decrease the two overlay process error of the a-IGZO-ESL and ES-S/D metallization layer in the conventional ESL process (Fig. 2). The overlay number of the a-IGZO, ES, and S/D layer is reduced, which resulted in the decrease in the size of TFT device that lowered the parasitic capacitance. The outcome planar structure is similar to the BCE structure (Fig. 3a, b).

(Color online) Schematics of simultaneous formation method for TFT channel and S/D electrode in CL-ES process. a The first step that forms gate electrode. b The second step that forms etch-stopper layer. c The third step that forms S/D photo pattern. d The fourth step that forms S/D electrode and active pattern

Figure 3 shows the SEM images of a-IGZO-based TFTs with CL-ES structure (Fig. 3a, c) and BCE structure (Fig. 3b, d). From the top view, it is difficult to identify the differences between CL-ES structure and BCE structure (Fig. 3a, b). From the side view, an ES nano-layer can be found between the a-IGZO nano-layer and the S/D electrode layer in CL-ES structure (Fig. 3c). Meanwhile, a passivation layer can be found on the top of a-IGZO nano-layer in BCE structure (Fig. 3d). In the presented CL-ES process, an a-IGZO nano-layer with a thickness of 30 nm is deposited. Moreover, the damage during wet etching is negligible. For BCE process, a 70-nm a-IGZO nano-layer is deposited, as a-IGZO layer needs compensation for etching loss. The difference between the thicknesses of a-IGZO nano-layers in CL-ES and BCE structures can be observed in the SEM images (Fig. 3c, d).

The I-V characteristics of a-IGZO-based TFT with CL-ES structure and BCE structure are compared (Fig. 4). The saturation electron mobility, threshold voltage, subthreshold voltage swing (SS) value, and more characteristic values are summarized in Table 1. Note that the values summarized in Table 1 are the average number derived from the center and edge of an 8.5 generation glass substrate. The a-IGZO-based TFT with CL-ES structure realizes Vth of − 0.8 V, SS value of 0.18 V/dec, and saturation electron mobility of 8.05 cm2/V s. In the a-IGZO-based TFT with BCE structure, the corresponding results are Vth of + 0.5 V, SS value of 0.77 V/dec, and saturation electron mobility of 6.03 cm2/V s. Compared to the BCE structure, CL-ES structure shows an improved device performances. However, the on-current characteristic of the a-IGZO-based TFT device with CL-ES structure is lower than that with BCE-structured device. This is due to the fact that TFT channel structures are different in CL-ES and BCE structures. Generally, BCE-structured TFT channel length are the distance between S/D metal electrodes, and the measured channel length in this study is 5 um [21]. In CL-ES structure, electrodes are in contact with the a-IGZO nano-film that is stretched at the side of ESL nano-mask. Therefore, the channel length is decided by the distance between the a-IGZOs defined at the etch-stopper’s sides, but not determined by the distance between the electrodes. The channel length of the present CL-ES-structure device is measured to be 10 um.

(Color online) Comparison of I-V characteristic of a-IGZO TFTs with CL-ES and BCE structure on the center (a) and edge (b) of 8.5 generation glass substrate

As shown in Table 1, the measured values of Ion/Ioff ratio (~ 106, see Table 1) are approximately 10 times smaller than the typical value (> 107) of a-IGZO-based TFTs. This is because the measuring equipment used here is for the 8.5 generation mass production. Long cables are necessary for these measurements, as the size of the industrial equipment is large. The long cables resulted in an increased measurement noise. In the following reliability testing, smaller-scale measuring equipment is utilized, and the individual TFT devices is used as specimen for measurement. In this way, the measured Ion/Ioff ratios are all upper 107 (see below).

CL-ES process is carefully designed to prevent a-IGZO channel layer being exposed to etchant, photoresist, or stripper. During the process that produces CL-ES process, gate insulator, a-IGZO nano-layer, and ES nano-layer, each inter-layer interface is in contact with only DI water for cleaning purpose. Hence, the chemical contamination is negligible in insulator layer and a-IGZO nano-layer [25, 26]. However, the BCE process not only exposes channel layer to the chemicals but also involves Cu ion diffusion contamination, as the a-IGZO channel is directly exposed to Cu metal. This is also avoided in device with CL-ES structure. The channel region of the a-IGZO nano-film is well protected by ESL nano-mask. The low chemical contamination in CL-ES process may lead to a low carrier trap density at the interface between a-IGZO nano-layer and insulator layer, resulting in an excellent SS value. This low chemical contamination of a-IGZO-based TFT device via CL-ES process also helps improve the uniformity and reproducibility of a-IGZO TFT, which are highly important in industrial production [27, 28].

Figure 5 shows the measured I-V characteristic of TFTs with CL-ES structure and BCE structure derived from 42 measuring points on an 8.5 generation substrate. a-IGZO-based TFT with CL-ES structure has a Vth range of 0.72 V, while that of BCE-structured device is 2.14 V (Table 1). In other words, the uniformity of device performance is significantly improved by CL-ES structure.

(Color online) a CL-ES structure. b BCE structure’s TFTs I-V transfer characteristic. c 42 measuring points. d the photo of TFT. All measured on an 8.5 generation substrate

Figure 6a, b show the I-V characteristic shift of CL-ES-structured device and BCE-structured device obtained in NBTIS testing, respectively. The NBTIS testing results are summarized in Table 2. Under the stress condition described in the Table 2, the Vth shift of CL-ES-structured device and BCE-structured device are − 0.51 and − 3.88 V, respectively. Additionally, the on-current shift, off-current shift, and SS value variance of the CL-ES-structured device are all lower than those of the BCE-structured device (Table 2); this is because a-IGZO-based device with CL-ES-structure can effectively prevent the contamination of a-IGZO and lower carrier trap density of a-IGZO TFT channel. Especially, when looking at the result from first 1000 s of stress, no SS value change is observed in CL-ES-structured device. This phenomenon is comparable to the 0.16 V/dec increase in SS value of BCE-structured device, as it shows that defect sites, which can form carrier traps on the surface of a-IGZO nano-film constituting CL-ES TFT back channel, are not additionally created by electrical and illumination stress. These results fully prove that CL-ES-structured device is much more stable than BCE-structured device. Figure 6c, d show the I-V curve shift of CL-ES- and BCE-structured TFTs obtained from PBTS testing. The detailed PBTS testing results are summarized in Table 3. Both CL-ES-structured TFT and BCE-structured TFT have decreased in ion current during PBTS evaluation. This is caused by the shift in Vth to the positive direction. During PBTS evaluation, residual ion current ratio [(last ion/initial ion) × 100] of the CL-ES-structured TFT with relatively smaller Vth positive shift (+ 1.94 V) is in the level of 88.2%. When compared to the BCE-structured TFT"s residual ion current ratio of 41.3%, CL-ES-structured TFT is significantly superior. This shows the important capacity difference during designing of gate drive on array (GOA) circuit. Different from NBTIS, SS value of CL-ES-structured TFT does not have significant variation ((∆SS 0.06 V/dec), or rather decreases (∆SS − 0.86) like as BCE-structured TFT. This is perhaps due to the carriers, accumulate in the inner space and interface between gate insulator and a-IGZO nano-film by positive gate bias, filling the carrier trap site at the early stage, causing decrease in carrier trap phenomenon. Moreover, the threshold voltage shift phenomenon occurs by carrier charge trapped near the interface between gate insulator and a-IGZO nano-film. Small threshold voltage shift of CL-ES-structured TFT represents that the interface and the inner space of a-IGZO are remarkably clean. In conclusion, PBTS testing also suggests that CL-ES structure and process lead to a better device reliability.