In a negatively-chargeable laminate-type electrophotographic photoreceptor, a charge generation layer and another charge transport layer are arranged on a conductive substrate directly or via an intermediate layer. The charge transport layer contains at least a hole-transporting substance, an electron-transporting substance and a binder resin; the mass ratio (R.sub.PN) [% by mass] between mass (P) of the hole-transporting substance and mass (N) of the electron-transporting substance is represented by the following equation (1), and satisfies the following equation (2):
R.sub.PN=(N/(P+N))100(1)
1R.sub.PN40(2); and
when a voltage of +6 kV is applied to the photoreceptor for 5 seconds via a resin sheet having a thickness of 50 m and a surface resistivity of 210.sup.7 /cm.sup.2, the surface potential difference (Vo) and half-tone potential difference (Vh) between before and after the voltage application are both 15 V or less.

An electrophotographic photosensitive member can provide images in which black spots and fogging are suppressed and density unevenness due to coating unevenness of the charge generation layer is suppressed. The charge generation layer of the electrophotographic photosensitive member contains a gallium phthalocyanine crystal, a nitrogen-containing heterocyclic compound, and an amide compound represented by a formula (1), and a nitrogen atom in a heterocyclic ring of the nitrogen-containing heterocyclic compound has a substituent. ##STR00001##

In a negatively-chargeable laminate-type electrophotographic photoreceptor, a charge generation layer and another charge transport layer are arranged on a conductive substrate directly or via an intermediate layer. The charge transport layer contains at least a hole-transporting substance, an electron-transporting substance and a binder resin; the mass ratio (R.sub.PN) [% by mass] between mass (P) of the hole-transporting substance and mass (N) of the electron-transporting substance is represented by the following equation (1), and satisfies the following equation (2):

R.sub.PN=(N/(P+N))100(1)

1R.sub.PN40(2); and

when a voltage of +6 kV is applied to the photoreceptor for 5 seconds via a resin sheet having a thickness of 50 m and a surface resistivity of 210.sup.7 /cm.sup.2, the surface potential difference (Vo) and half-tone potential difference (Vh) between before and after the voltage application are both 15 V or less.

A triarylamine derivative represented by general formula (1) below. In the general formula (1), R.sub.1, R.sub.2, R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8, and R.sub.9 each represent, independently from one another, a hydrogen atom, an optionally substitute alkyl group having a carbon number of at least 1 and no greater than 6, an optionally substituted alkoxy group having a carbon number of at least 1 and no greater than 6, or an optionally substituted aryl group having a carbon number of at least 6 and no greater than 14, R.sub.3 represents an alkyl group having a carbon number of at least 1 and no greater than 4, X represents an alkylene group having a carbon number of at least 1 and no greater than 6 or an oxygen atom, and n represents an integer of 1 to 3.

##STR00001##

Provided is a lamination-type electrophotographic photoreceptor comprising a conductive substrate, and a charge transport layer and a charge generation layer both on the conductive substrate, wherein the charge transport layer comprises a charge transport substance represented by the general formula (1), a binder resin, and a particulate silicon compound.

An electrophotographic photosensitive member has a photosensitive layer. The photosensitive layer is a multi-layer photosensitive layer having a charge transport layer being an outermost layer or a single-layer photosensitive layer. The amount of silica particles contained in the photosensitive layer is at least 0.5 parts by mass and no greater than 15 parts by mass relative to 100 parts by mass of a binder resin contained in the photosensitive layer.

An electrophotographic photoreceptor includes a conductive support; and an undercoat layer and a photosensitive layer stacked on the conductive support, in which the undercoat layer contains crystalline electron transport compound particles. In X-ray diffraction measurement performed on the undercoat layer in a thickness direction, a maximum intensity peak has a half-width of 5 or less, and a maximum value Nmax among orientation indices N expressed by equation (1) below is 1 or more and 3 or less: $\begin{array}{cc}\mathrm{Orientation}\mathrm{index}=\frac{\frac{I_1}{.Math.I_1}}{\frac{I_2}{.Math.I_2}}& \left(1\right)\end{array}$ where I.sub.1 represents a relative integral intensity of each of peaks in the X-ray diffraction measurement performed on the undercoat layer in the thickness direction, and I.sub.2 represents a relative integral intensity of each of peaks in X-ray diffraction measurement performed on the undercoat layer processed into a powder form having a volume-average particle diameter of 5m or less.